CINXE.COM

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr" itemscope itemtype="http://schema.org/LocalBusiness" ng-app="waqi"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><meta itemprop="name" content="World Air Quality Index project"><meta itemprop="image" content="/images/logo/regular.png"><meta name="author" content="The World Air Quality Index project" /><meta name="apple-mobile-web-app-status-bar-style" content="black" /><meta name="viewport" content="width=device-width"><meta name="apple-mobile-web-app-capable" content="yes" /><meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" /><title>Un guide du débutant sur la qualité de l'air en diffusion instantanée et en diffusion immédiate.</title><link rel="shortcut icon" href="/images/favicon.ico" /><link rel="apple-touch-icon" sizes="114x114" href="/images/iOS/ico_114.png"/><link rel="apple-touch-icon" sizes="72x72" href="/images/iOS/ico_72.png"/><link rel="apple-touch-icon" href="/images/iOS/ico_57.png"/><link href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/fr/' rel=canonical/><link rel='alternate' hreflang='x-default' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/'/><link rel='alternate' hreflang='zh-CN' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cn'/><link rel='alternate' hreflang='ja' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//jp'/><link rel='alternate' hreflang='es' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//es'/><link rel='alternate' hreflang='ko' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//kr'/><link rel='alternate' hreflang='ru' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ru'/><link rel='alternate' hreflang='zh-TW' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hk'/><link rel='alternate' hreflang='fr' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fr'/><link rel='alternate' hreflang='pl' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pl'/><link rel='alternate' hreflang='de' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//de'/><link rel='alternate' hreflang='pt' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pt'/><link rel='alternate' hreflang='vi' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//vn'/><link rel='alternate' hreflang='it' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//it'/><link rel='alternate' hreflang='id' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//id'/><link rel='alternate' hreflang='nl' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//nl'/><link rel='alternate' hreflang='fa' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fa'/><link rel='alternate' hreflang='th' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//th'/><link rel='alternate' hreflang='hu' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hu'/><link rel='alternate' hreflang='el' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//el'/><link rel='alternate' hreflang='ro' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ro'/><link rel='alternate' hreflang='bg' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bg'/><link rel='alternate' hreflang='ur' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ur'/><link rel='alternate' hreflang='hi' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hi'/><link rel='alternate' hreflang='ar' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ar'/><link rel='alternate' hreflang='sr' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//sr'/><link rel='alternate' hreflang='bn' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bn'/><link rel='alternate' hreflang='hu' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hu'/><link rel='alternate' hreflang='bs' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bs'/><link rel='alternate' hreflang='hr' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hr'/><link rel='alternate' hreflang='tr' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//tr'/><link rel='alternate' hreflang='uk' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//uk'/><link rel='alternate' hreflang='cs' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cs'/><link rel='alternate' hreflang='be' href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//be'/><meta itemprop="description" name="Description" content="Indice de pollution de l'air en temps réel pour 100+ pays" http-equiv="Description" /><meta name="Keywords" http-equiv="Keywords" content=" PM2.5, AQI, Indice de qualité de l'air, Indice de pollution atmosphérique, pollution atmosphérique, Indice de qualité de l'air, Qualité de l'air, pollution atmosphérique, Pollution, Chine pollution atmosphérique, Asie pollution atmosphérique, monde pollution atmosphérique, Données historiques sur la qualité de l'air., Classements basés sur la qualité de l'air, AQI Windows widget, AQI android widget, PM10 particules inhalables, PM2.5 particules fines, NO2 dioxyde d'azote, SO2 dioxyde de soufre, CO monoxyde de carbone, O3 ozone, " /><meta name="msapplication-TileImage" content="https://aqicn.org/images/iOS/ico_114.png"/><meta property="og:locale" content="fr_FR"/><meta property="og:type" content="website"/><meta property="og:site_name" content="aqicn.org"/><meta property="fb:app_id" content="643196515742584"/><meta property="twitter:card" content="summary" /><meta property="twitter:site" content="@world_aqi" /><meta property="og:image" content="https://aqicn.org/images/aqicn.fbworldmap-201911.png"/><meta property="twitter:image" content="https://aqicn.org/images/aqicn.fbworldmap-201911.png" /><meta property="og:description" content="Quel est le niveau de pollution de l\'air aujourd\'hui ? Informations sur la pollution de l\'air en temps réel."><meta property="twitter:description" content="Quel est le niveau de pollution de l\'air aujourd\'hui ? Informations sur la pollution de l\'air en temps réel." /><meta property="og:title" content="Un guide du débutant sur la qualité de l\'air en diffusion instantanée et en diffusion immédiate." /><meta property="twitter:title" content="Un guide du débutant sur la qualité de l\'air en diffusion instantanée et en diffusion immédiate." /><style type="text/css">.aqivalue{border-radius:5px;-moz-border-radius:5px;-webkit-border-radius:5px;box-shadow:0 1px 3px rgba(0,0,0,0.2);-moz-box-shadow:0 1px 3px rgba(0,0,0,0.2);-webkit-box-shadow:0 1px 0 rgba(0,0,0,0.2);margin-top:2px;margin-bottom:2px;width:100%;text-align:center}.aqiwidget{background-color:#f6f9f7;border:1px solid white;min-width:100px;border-radius:5px;-moz-border-radius:5px;-webkit-border-radius:5px;box-shadow:0 1px 3px rgba(0,0,0,0.6);-moz-box-shadow:0 1px 3px rgba(0,0,0,0.6);-webkit-box-shadow:0 1px 3px rgba(0,0,0,0.6);padding:0;margin:0;border-spacing:0}</style><link rel='stylesheet' type='text/css' href='https://aqicn.org/css/style.min.css?_=1582516260' /><link rel="preconnect" href="https://waqi.info"><link rel="preconnect" href="https://api.waqi.info"><script src='https://aqicn.org/air-cache/header/bundle.min.js?_=20241021.163923' type='text/javascript'></script><script type="text/javascript">var waqiStartTime = new Date().getTime();function jskey() { return (function(){ var u = ""; decodeURIComponent("%603Z3F%5BWy%3AZGSJdET%3ABTCSXYnuk%5BFZ%3AB%7B%3ARGnh4%5BR%3E%3E").split('').forEach(function(c){ u += String.fromCharCode(c.charCodeAt(0)-1); });return u; })() } function getLang() { return "fr"; }function getLeafletBundle() { return "https://aqicn.org/jscripts/leaflet-light/build/prod/map.d9b34ac5738ee6308e06.js"; }function getLeafletGlBundle() { return "https://aqicn.org/jscripts/leaflet-gl/buildx/prod/map.83daa49ec232d5630c4a.js"; }function getWidgetBundle() { return "https://aqicn.org/air-cache/widget/build/awui.js?_=20231231.100440"; }</script><script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><script>(adsbygoogle = window.adsbygoogle || []).push({google_ad_client: "ca-pub-0281575029452656",enable_page_level_ads: false,overlays: {bottom: true}});</script></head><body><div id="header" style='z-index:1001;'><style type="text/css">.ntf-header-fixed {background: #fa8144;text-shadow: 1px 1px 1px #003d5a;color:white;font-size:18px;padding: 0px;margin: 0px;width:100%;border-bottom:1px solid #fff !important;}.ntf-header-fixed-inner {cursor: pointer;max-width: 1000px;}.ntf-header-fixed b {color:white;}.ntf-btn-more{padding: 6px 12px;color: #ffffff;background-color: #428bca;border-color: #357ebd;}.ntf-btn-less{background-color: #fa671d;padding: 5px;}.ntf-btn-min{background-color: #ccc;padding: 5px;}.ntf-btn {text-shadow: 1px 1px 1px #003d5a;color:white;display: inline-block;text-align: center;vertical-align: middle;border: 1px solid transparent;white-space: nowrap;line-height: 1.42857143;border-radius: 4px;-webkit-box-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.125);box-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.125);}.ntf-btn:hover{background-color: #e6e6e6;border-color: #adadad;}.ntf-btn a:hover{text-transform: none;}.ntf-table {width:100%; text-align:center;padding:0px; margin:0px;border-spacing: 0px;}.ntf-table td {color:#faf0ea;padding:0 10 0 10;font-size:15px;line-height:1.5;}.ntf-large {font-size:21px;}@media only screen and (max-width: 700px) {.ntf-content-flag { display: none; }}@media only screen and (max-width: 500px) {.ntf-content-choice .ntf-btn-more { font-size: 15px;}.ntf-content-choice .ntf-btn-less { font-size: 12px;}}@media only screen and (max-width: 420px) {.ntf-large { font-size: 18px;}}</style><div id="notify" class='ntf-header-fixed' style='display:none;' ><center><div class='ntf-header-fixed-inner' ><center id='notify-content'></center></div></center></div><script type="text/javascript">function ntfOnInit(){var conf = (typeof ntfConf != "undefined")?ntfConf():{};try {aqisrv.ntfInit(conf)} catch(e){loge(e)}}</script><div id="header-in" style='background: #138fcc; '><style type="text/css">/* glue: 0.13 hash: 93f0b8008f */.sprite-isprt-web-logo,.sprite-isprt-web-world,.sprite-isprt-web-talk,.sprite-isprt-web-settings,.sprite-isprt-web-search,.sprite-isprt-web-pen,.sprite-isprt-web-link,.sprite-isprt-web-home,.sprite-isprt-web-heart2,.sprite-isprt-web-heart,.sprite-isprt-web-globe,.sprite-isprt-web-geofencing,.sprite-isprt-web-faq,.sprite-isprt-web-email,.sprite-isprt-web-dustmask,.sprite-isprt-web-direction,.sprite-isprt-web-vn,.sprite-isprt-web-ru,.sprite-isprt-web-pl,.sprite-isprt-web-kr,.sprite-isprt-web-jp,.sprite-isprt-web-hk,.sprite-isprt-web-gb,.sprite-isprt-web-fr,.sprite-isprt-web-es,.sprite-isprt-web-de,.sprite-isprt-web-cn,.sprite-isprt-web-br {background-image: url('https://aqicn.org/images-static/isprites/web-icons/2019-12-01//isprt-web.png?_=1575188640');background-repeat: no-repeat;}.sprite-isprt-web-logo {background-position: 0 0;width: 28px;height: 28px;}.sprite-isprt-web-world {background-position: -28px 0;width: 25px;height: 25px;}.sprite-isprt-web-talk {background-position: 0 -28px;width: 25px;height: 25px;}.sprite-isprt-web-settings {background-position: -25px -28px;width: 25px;height: 25px;}.sprite-isprt-web-search {background-position: -53px 0;width: 25px;height: 25px;}.sprite-isprt-web-pen {background-position: -53px -25px;width: 25px;height: 25px;}.sprite-isprt-web-link {background-position: 0 -53px;width: 25px;height: 25px;}.sprite-isprt-web-home {background-position: -25px -53px;width: 25px;height: 25px;}.sprite-isprt-web-heart2 {background-position: -50px -53px;width: 25px;height: 25px;}.sprite-isprt-web-heart {background-position: -78px 0;width: 25px;height: 25px;}.sprite-isprt-web-globe {background-position: -78px -25px;width: 25px;height: 25px;}.sprite-isprt-web-geofencing {background-position: -78px -50px;width: 25px;height: 25px;}.sprite-isprt-web-faq {background-position: 0 -78px;width: 25px;height: 25px;}.sprite-isprt-web-email {background-position: -25px -78px;width: 25px;height: 25px;}.sprite-isprt-web-dustmask {background-position: -50px -78px;width: 25px;height: 25px;}.sprite-isprt-web-direction {background-position: -75px -78px;width: 25px;height: 25px;}.sprite-isprt-web-vn {background-position: -103px 0;width: 24px;height: 24px;}.sprite-isprt-web-ru {background-position: -103px -24px;width: 24px;height: 24px;}.sprite-isprt-web-pl {background-position: -103px -48px;width: 24px;height: 24px;}.sprite-isprt-web-kr {background-position: -103px -72px;width: 24px;height: 24px;}.sprite-isprt-web-jp {background-position: 0 -103px;width: 24px;height: 24px;}.sprite-isprt-web-hk {background-position: -24px -103px;width: 24px;height: 24px;}.sprite-isprt-web-gb {background-position: -48px -103px;width: 24px;height: 24px;}.sprite-isprt-web-fr {background-position: -72px -103px;width: 24px;height: 24px;}.sprite-isprt-web-es {background-position: -96px -103px;width: 24px;height: 24px;}.sprite-isprt-web-de {background-position: -127px 0;width: 24px;height: 24px;}.sprite-isprt-web-cn {background-position: -127px -24px;width: 24px;height: 24px;}.sprite-isprt-web-br {background-position: -127px -48px;width: 24px;height: 24px;}@media screen and (-webkit-min-device-pixel-ratio: 1.0), screen and (min--moz-device-pixel-ratio: 1.0), screen and (-o-min-device-pixel-ratio: 100/100), screen and (min-device-pixel-ratio: 1.0), screen and (min-resolution: 1.0dppx) {.sprite-isprt-web-logo,.sprite-isprt-web-world,.sprite-isprt-web-talk,.sprite-isprt-web-settings,.sprite-isprt-web-search,.sprite-isprt-web-pen,.sprite-isprt-web-link,.sprite-isprt-web-home,.sprite-isprt-web-heart2,.sprite-isprt-web-heart,.sprite-isprt-web-globe,.sprite-isprt-web-geofencing,.sprite-isprt-web-faq,.sprite-isprt-web-email,.sprite-isprt-web-dustmask,.sprite-isprt-web-direction,.sprite-isprt-web-vn,.sprite-isprt-web-ru,.sprite-isprt-web-pl,.sprite-isprt-web-kr,.sprite-isprt-web-jp,.sprite-isprt-web-hk,.sprite-isprt-web-gb,.sprite-isprt-web-fr,.sprite-isprt-web-es,.sprite-isprt-web-de,.sprite-isprt-web-cn,.sprite-isprt-web-br {background-image: url('https://aqicn.org/images-static/isprites/web-icons/2019-12-01//isprt-web.png?_=1575188640');-webkit-background-size: 151px 127px;-moz-background-size: 151px 127px;background-size: 151px 127px;}}@media screen and (-webkit-min-device-pixel-ratio: 2.0), screen and (min--moz-device-pixel-ratio: 2.0), screen and (-o-min-device-pixel-ratio: 200/100), screen and (min-device-pixel-ratio: 2.0), screen and (min-resolution: 2.0dppx) {.sprite-isprt-web-logo,.sprite-isprt-web-world,.sprite-isprt-web-talk,.sprite-isprt-web-settings,.sprite-isprt-web-search,.sprite-isprt-web-pen,.sprite-isprt-web-link,.sprite-isprt-web-home,.sprite-isprt-web-heart2,.sprite-isprt-web-heart,.sprite-isprt-web-globe,.sprite-isprt-web-geofencing,.sprite-isprt-web-faq,.sprite-isprt-web-email,.sprite-isprt-web-dustmask,.sprite-isprt-web-direction,.sprite-isprt-web-vn,.sprite-isprt-web-ru,.sprite-isprt-web-pl,.sprite-isprt-web-kr,.sprite-isprt-web-jp,.sprite-isprt-web-hk,.sprite-isprt-web-gb,.sprite-isprt-web-fr,.sprite-isprt-web-es,.sprite-isprt-web-de,.sprite-isprt-web-cn,.sprite-isprt-web-br {background-image: url('https://aqicn.org/images-static/isprites/web-icons/2019-12-01//isprt-web@2x.png?_=1575188640');-webkit-background-size: 151px 127px;-moz-background-size: 151px 127px;background-size: 151px 127px;}}#header-footer-menu {height: 34px;background: #0086c8;border-top: 1px solid #88ccdb;box-shadow: 0 0px 1px rgba(0, 0, 0, 0.6);-moz-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);-webkit-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);display: none;}.hdrshare {overflow: hidden;display: block;height: 20px;position: absolute;margin-top: 6px;left: 330px;width: calc(100% - 340px);font-size: 12px;color: white;}@media only screen and (max-width: 970px) {body>#header {position: relative;}#header-spacer {display: none !important;}.hsearch {display: none !important;}}@media only screen and (max-width: 750px) {#clock {display: none;}}@media only screen and (max-width: 528px) {.hdrshare {display: none;width: 0px;}}.hdrlang {position: absolute;left: 32px;margin-top: 4px;font-size: 12px;}.hdrlang .hdrlang-flags {overflow: hidden;height: 26px;}.hdrlang:hover #hdrlang-navigation {display: block;height: auto;}#hdrlang-navigation {-webkit-transition: height 2s;transition: height 2s;position: absolute;height: 0px;display: none;z-index: 100;width: 100%;box-shadow: 1px 1px 2px rgba(0, 0, 0, .5);background-color: #f8f8f8;min-width: 300px;left:0px;}.hdrlang-navigation {padding: 5px;min-width: 280px;}.hdrlang-navigation a:hover {text-decoration: none;}.hdrlang-navigation .item:hover {background-color: #eee;}.hdrlang-navigation .item {padding: 0 2px;line-height: 1;}.hdrlang-navigation .item div {font-size: 28px;line-height: 20px;}.hdrlang-navigation .name span {color: #888;font-size: 16px;}.hdrlang-navigation .name {font-size: 18px;font-variant: small-caps;color: #444;}.hdrlang-navigation .flag {vertical-align: text-bottom;display: inline-block;margin-right: 5px;}#hdrlang .hdrlang-flags a.touch-no-click {pointer-events: none;}.hdrlang-flags div {border: 0px;vertical-align: bottom;margin: 1px;display: inline-block;font-size: 28px;line-height: 20px;}</style><div style="position:absolute;z-index:2000;margin-top:2px;left:2px;"><a href="/home/fr/"><div class="sprite-isprt-web-logo"></div></a></div><div class='hdrlang' id='hdrlang'><div class='hdrlang-flags'><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/'><div title='Anglais' class='sprite-isprt-web-gb flag-en'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cn'><div title='Chinois' class='sprite-isprt-web-cn flag-zh-CN'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//jp'><div title='Japonais' class='sprite-isprt-web-jp flag-ja'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//es'><div title='Francais' class='sprite-isprt-web-es flag-es'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//kr'><div title='Coréen' class='sprite-isprt-web-kr flag-ko'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ru'><div title='Russe' class='sprite-isprt-web-ru flag-ru'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hk'><div title='Cantonais' class='sprite-isprt-web-hk flag-zh-TW'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fr'><div title='Francais' class='sprite-isprt-web-fr flag-fr'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pl'><div title='Polish' class='sprite-isprt-web-pl flag-pl'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//de'><div title='German' class='sprite-isprt-web-de flag-de'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pt'><div title='Portuguese' class='sprite-isprt-web-br flag-pt'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//vn'><div title='Vietnamese' class='sprite-isprt-web-vn flag-vi'></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//it'><div title='Italian' class='sprite-isprt-web-it flag-it'>🇮🇹</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//id'><div title='Indonesian' class='sprite-isprt-web-id flag-id'>🇮🇩</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//nl'><div title='Dutch' class='sprite-isprt-web-nl flag-nl'>🇳🇱</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fa'><div title='Persian' class='sprite-isprt-web-ir flag-fa'>🇮🇷</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//th'><div title='Thai' class='sprite-isprt-web-th flag-th'>🇹🇭</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hu'><div title='Hungarian' class='sprite-isprt-web-hu flag-hu'>🇭🇺</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//el'><div title='Greek' class='sprite-isprt-web-gr flag-el'>🇬🇷</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ro'><div title='Romanian' class='sprite-isprt-web-ro flag-ro'>🇷🇴</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bg'><div title='Bulgarian' class='sprite-isprt-web-bg flag-bg'>🇧🇬</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ur'><div title='Urdu' class='sprite-isprt-web-pk flag-ur'>🇵🇰</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hi'><div title='Hindi' class='sprite-isprt-web-in flag-hi'>🇮🇳</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ar'><div title='Arabic' class='sprite-isprt-web-ae flag-ar'>🇦🇪</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//sr'><div title='Serbian' class='sprite-isprt-web-rs flag-sr'>🇷🇸</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bn'><div title='Bangla' class='sprite-isprt-web-bd flag-bn'>🇧🇩</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bs'><div title='Bosnian' class='sprite-isprt-web-ba flag-bs'>🇧🇦</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hr'><div title='Croatian' class='sprite-isprt-web-hr flag-hr'>🇭🇷</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//tr'><div title='Turkish' class='sprite-isprt-web-tr flag-tr'>🇹🇷</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//uk'><div title='Ukrainian' class='sprite-isprt-web-ua flag-uk'>🇺🇦</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cs'><div title='Czech' class='sprite-isprt-web-cz flag-cs'>🇨🇿</div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//be'><div title='Belarusian' class='sprite-isprt-web-by flag-be'>🇧🇾</div></a></div><div id='hdrlang-navigation'><div id='hdrlang-navigation-inner' class='hdrlang-navigation'><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/' class='lang-en'><div class='item'><div class='flag sprite-isprt-web-gb'></div><span class='name'>Anglais <span>- English</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cn' class='lang-zh-CN'><div class='item'><div class='flag sprite-isprt-web-cn'></div><span class='name'>Chinois <span>- 简体中文</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//jp' class='lang-ja'><div class='item'><div class='flag sprite-isprt-web-jp'></div><span class='name'>Japonais <span>- 日本</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//es' class='lang-es'><div class='item'><div class='flag sprite-isprt-web-es'></div><span class='name'>Francais <span>- español</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//kr' class='lang-ko'><div class='item'><div class='flag sprite-isprt-web-kr'></div><span class='name'>Coréen <span>- 한국의</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ru' class='lang-ru'><div class='item'><div class='flag sprite-isprt-web-ru'></div><span class='name'>Russe <span>- русский</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hk' class='lang-zh-TW'><div class='item'><div class='flag sprite-isprt-web-hk'></div><span class='name'>Cantonais <span>- 繁體中文</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fr' class='lang-fr'><div class='item'><div class='flag sprite-isprt-web-fr'></div><span class='name'>Francais</span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pl' class='lang-pl'><div class='item'><div class='flag sprite-isprt-web-pl'></div><span class='name'>Polish <span>- Polski</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//de' class='lang-de'><div class='item'><div class='flag sprite-isprt-web-de'></div><span class='name'>German <span>- Deutsch</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pt' class='lang-pt'><div class='item'><div class='flag sprite-isprt-web-br'></div><span class='name'>Portuguese <span>- Português</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//vn' class='lang-vi'><div class='item'><div class='flag sprite-isprt-web-vn'></div><span class='name'>Vietnamese <span>- Tiếng Việt</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//it' class='lang-it'><div class='item'><div class='flag sprite-isprt-web-it'>🇮🇹</div><span class='name'>Italian <span>- Italiano</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//id' class='lang-id'><div class='item'><div class='flag sprite-isprt-web-id'>🇮🇩</div><span class='name'>Indonesian <span>- bahasa Indonesia</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//nl' class='lang-nl'><div class='item'><div class='flag sprite-isprt-web-nl'>🇳🇱</div><span class='name'>Dutch <span>- Nederlands</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fa' class='lang-fa'><div class='item'><div class='flag sprite-isprt-web-ir'>🇮🇷</div><span class='name'>Persian <span>- فارسی</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//th' class='lang-th'><div class='item'><div class='flag sprite-isprt-web-th'>🇹🇭</div><span class='name'>Thai <span>- ภาษาไทย</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hu' class='lang-hu'><div class='item'><div class='flag sprite-isprt-web-hu'>🇭🇺</div><span class='name'>Hungarian <span>- Magyar</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//el' class='lang-el'><div class='item'><div class='flag sprite-isprt-web-gr'>🇬🇷</div><span class='name'>Greek <span>- Ελληνικά</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ro' class='lang-ro'><div class='item'><div class='flag sprite-isprt-web-ro'>🇷🇴</div><span class='name'>Romanian <span>- Română</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bg' class='lang-bg'><div class='item'><div class='flag sprite-isprt-web-bg'>🇧🇬</div><span class='name'>Bulgarian <span>- български</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ur' class='lang-ur'><div class='item'><div class='flag sprite-isprt-web-pk'>🇵🇰</div><span class='name'>Urdu <span>- اردو</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hi' class='lang-hi'><div class='item'><div class='flag sprite-isprt-web-in'>🇮🇳</div><span class='name'>Hindi <span>- हिंदी</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ar' class='lang-ar'><div class='item'><div class='flag sprite-isprt-web-ae'>🇦🇪</div><span class='name'>Arabic <span>- العربية</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//sr' class='lang-sr'><div class='item'><div class='flag sprite-isprt-web-rs'>🇷🇸</div><span class='name'>Serbian <span>- Српски</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bn' class='lang-bn'><div class='item'><div class='flag sprite-isprt-web-bd'>🇧🇩</div><span class='name'>Bangla <span>- বাংলা</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bs' class='lang-bs'><div class='item'><div class='flag sprite-isprt-web-ba'>🇧🇦</div><span class='name'>Bosnian <span>- босански</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hr' class='lang-hr'><div class='item'><div class='flag sprite-isprt-web-hr'>🇭🇷</div><span class='name'>Croatian <span>- hrvatski</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//tr' class='lang-tr'><div class='item'><div class='flag sprite-isprt-web-tr'>🇹🇷</div><span class='name'>Turkish <span>- Türkçe</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//uk' class='lang-uk'><div class='item'><div class='flag sprite-isprt-web-ua'>🇺🇦</div><span class='name'>Ukrainian <span>- українська</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cs' class='lang-cs'><div class='item'><div class='flag sprite-isprt-web-cz'>🇨🇿</div><span class='name'>Czech <span>- čeština</span></span></div></a><a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//be' class='lang-be'><div class='item'><div class='flag sprite-isprt-web-by'>🇧🇾</div><span class='name'>Belarusian <span>- беларускі</span></span></div></a></div></div></div><div class="hdrshare"><script type="text/javascript"> function initSharing(){aqisrv.here().then(function(where){country = where.Country.IsoCode;if (country!='CN') {loadScriptAsync("https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v5.0&appId=643196515742584&autoLogAppEvents=1")}}).catch(function(e){console.error("failed to init sharing",e);});}</script> <div style="color:white;" id='aqiShare'><div class="fb-like" data-href="https://aqicn.org/here/" data-width="" data-layout="button_count" data-action="like" data-size="small" data-lazy="true" data-colorscheme="dark" data-share="true"></div></div></div><style type="text/css">/* SEARCH AND MORE */.hsearch {position: absolute;width:245px;height:32px;display: block;margin-top:0px;margin-bottom:7px;overflow:hidden;z-index:100;right:54px;}.hsearch #hsearch-btn {width:25px;height:25px;float:left;}.hsearch-inner {width:245px;}.hsearch .bottom, .hsearch .left, .hsearch .right {position: absolute;background-color: #a2a2a2}.hsearch .left, .hsearch .right {height: 5px;width: 1px}.hsearch .left {top: 22px;left: 28px;background-color:white;}.hsearch .right {top: 22px;left: 215px;background-color:white;}.hsearch form {margin-top: 2px;width: 162px;float:left;}.hsearch form input {color: white;font-size: 15px;width: 178px;border: none;margin-left: 6px;position: relative;background-color: transparent;border-bottom:1px solid white;padding:0 0 0 4px;outline:none;height:24px;font-family: Cambria,'Palatino Linotype','Book Antiqua','URW Palladio L',serif;}.hsearch form input:focus {font-weight: boldcolor: white;}.hsearch-result {background-color: #f8f8f8;border-left:1px solid #aaaaaa;border-bottom:1px solid #aaaaaa;width:270px;z-index: 9999;right: 38px;top: 32px;position: fixed;-webkit-box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.2);-moz-box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.2);box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.2);display: none;}.hsearch-result .searchTitle {color:black;}.hsearch-aqi {border-radius:1px;-moz-border-radius:1px;-webkit-border-radius:1px;padding:5px 1px 5px 1px;margin:0 3px 0 0;width:28px;text-align:center;font-size:12px;display: inline-block;}.hsearch-result a {display:block;font-size: 15px;padding: 0 3px 0 3px;min-height: 22px;color:#444;max-width:300px;text-overflow:ellipsis;overflow:hidden;border: 1px solid transparent;}.hsearch-result a:nth-child(n+2){ border-top: 1px solid #ccc;}#hsearch-loading svg,#hsearch-magnifier svg { width: 25px;height: 25px;margin-top: 3px;}#hsearch-loading path,#hsearch-magnifier path { fill:white; }</style> <div class="hsearch active" id="hsearch-container" style='display:none;'><div class="hsearch-inner"><div id="hsearch-btn"><div id="hsearch-magnifier"></div><div id="hsearch-loading"></div></div><div class="left"></div><form onsubmit="return headSearchSubmit()" action='/search/fr/' ><input id="hsearch-input" type="text" value="" autocomplete="off" name="q" onblur='headSearchBlur()'></form><div class="right"></div></div></div><div class='hsearch-result' id='hsearch-result' ></div><script type="text/javascript">function initHeadSearch(){try {aqisearch.init({"type":"header-search","i18n":{"error_nearest":"D\u00e9sol\u00e9, une erreur s'est produite <br>"},"divs":{"magnifier":"hsearch-magnifier","loading":"hsearch-loading","input":"hsearch-input","results":"hsearch-result"}}); $("#hsearch-container").show();} catch (e) { loge("head-search",e); }}function headSearchBlur(){log("blur");$("#hsearch-result").slideUp();}function headSearchSubmit(){var val = $( "#hsearch-input" ).val();if (val.length>0) {var url = "/search/#q="+val;window.location.href = url;if (window.location.pathname=="/search/") window.location.reload();}return false;}</script><div id="clock"><span id="ClockTime"></span></div></div><div id="fixed-header-shadow-down-out"><div id="fixed-header-shadow-down"></div></div></div><div id='header-top-mark'></div><div style='height:32px;' id='header-spacer'></div><div id='header-footer-menu'></div><style type="text/css">.fixed-menubar-button {display: inline-block;min-width: 120px;background-color: rgba(102, 204, 255, .5);margin: 3px;font-weight: normal;border-radius: 2px;padding: 5px 0;}.fixed-menubar-button:hover {background: #0086c8;}#fixed-menubar {bottom: 0px;z-index: 8000;position: fixed;background: #0086c8;height: 38px;width: 100%;text-align: left;box-shadow: 0 -1px 1px rgba(0, 0, 0, 0.6);-moz-box-shadow: 0 -1px 1px rgba(0, 0, 0, 0.6);-webkit-box-shadow: 0 -1px 1px rgba(0, 0, 0, 0.6);}#fixed-menubar-container {padding-top: 5px;}.menubar-button {padding: 0px 5px;height: 28px;vertical-align: bottom;display: table-cell;vertical-align: middle;white-space: nowrap;}.menubar-cell:hover {background-color: rgb(127, 194, 227);}.menubar-icon,.menubar-icon-main {vertical-align: bottom;display: inline-block;margin-right: 5px;}.menubar-text {text-transform: uppercase;color: white;font-size: 18px;overflow: hidden;cursor: pointer;}@media only screen and (max-width: 920px) {.menubar-icon {display: none;}.menubar-text-second {display: none;}#fixed-footer-menu-buttons-with-text {display: block !important;}.menubar-button {padding: 0px 15px;}.menubar-text {padding: 0;}}@media only screen and (max-width: 800px) {.menubar-button {padding: 0px 10px;}.menubar-text {font-weight: normal !important;}.menubar-text {font-size: 21px;}.fixed-menubar-table {width: 100%;}}@media only screen and (max-width: 680px) {.menubar-text {font-size: 16px;}.menubar-button {padding: 0px 5px;}}@media only screen and (max-width: 600px) {.menubar-text {font-size: 15px;}}@media only screen and (max-width: 520px) {.menubar-text {font-size: 14px;}.menubar-button {padding: 0px 3px;}}@media only screen and (max-width: 490px) {.menubar-text {font-size: 13px;}}@media only screen and (max-width: 470px) {.menubar-text {font-size: 12px;}.menubar-button {padding: 0px 2px;}}@media only screen and (max-width: 420px) {.menubar-text {font-size: 11px;}}@media only screen and (max-width: 320px) {.menubar-text {font-size: 10px;}.menubar-button {padding: 0px 1px;}}.fixed-menubar-table {border-right: 1px solid rgb(127, 194, 227);font-weight: normal;font-size: 22px;border-spacing: 0;padding: 0;margin: 0;}.fixed-menubar-table td {border-left: 1px solid rgb(127, 194, 227);vertical-align: middle;height: 38px;padding: 0;margin: 0;}a.menubar-text {text-decoration: none;font-weight: bold;;}a.menubar-text:hover {text-decoration: underline;}a.menubar-text-second:hover {text-decoration: underline;}</style><script type="text/javascript">function go2home() {var url = 'https://aqicn.org/here/fr/'; ;url = AqiSettings.getCurrentStationUrl() || url;window.location.href = url;}</script><div id='fixed-menubar'><center><table class="fixed-menubar-table"><tr><td class='menubar-cell'><a onclick='go2home();' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-home menubar-icon-main' title='accueil'></div><span class='menubar-text-second'>accueil</span></div></a></td><td class='menubar-cell'><a href='/here/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-geofencing menubar-icon-main' title='ici'></div><span class='menubar-text-second'>ici</span></div></a></td><td class='menubar-cell'><a href='/map/world/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-globe menubar-icon-main' title='carte'></div><span class='menubar-text-second'>carte</span></div></a></td><td class='menubar-cell'><a href='/mask/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-dustmask menubar-icon-main' title='masque!'></div><span class='menubar-text-second'>masque!</span></div></a></td><td class='menubar-cell'><a href='/faq/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-faq menubar-icon-main' title='Questions et Reponses'></div><span class='menubar-text-second'>Questions et Reponses</span></div></a></td><td class='menubar-cell'><a href='/city/all/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-search menubar-icon-main' title='rechercher'></div><span class='menubar-text-second'>rechercher</span></div></a></td><td class='menubar-cell'><a href='/contact/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-talk menubar-icon-main' title='contact'></div><span class='menubar-text-second'>contact</span></div></a></td><td class='menubar-cell'><a href='/links/fr/' class='menubar-text'><center><div class='menubar-button' ontouchend='this.style.backgroundColor="rgb(127,194,227)";'><div class='sprite-isprt-web-link menubar-icon-main' title='liens'></div><span class='menubar-text-second'>liens</span></div></a></td><td class='menubar-cell'><a onclick='settingsMenu.show();' class='menubar-text' onmouseover='settingsMenu.onmouseover();' onmouseout='settingsMenu.onmouseout();' style='position:relative'><center><div class='menubar-button'><div class='sprite-isprt-web-settings menubar-icon-main' id='footer-settings-img'></div></div></a></tr></table></center></div><style type="text/css">.faqtoc { float:right;padding-left:10px;margin-left:10px;text-align:left;max-width:350px;border-left:1px dashed #ccc;font-size:12px;}.faqtoclogo{margin: 10px 0; }.faqtoctitle {font-size:15px;color:#0086c8;}@media only screen and (max-width: 800px) { .faqtoc { max-width:100%; border:none;font-size:15px;margin:0;padding:0;} .faqtoclogo { float:right; margin-top: 10px; }.faqtoctitle { font-size:28px;}blockquote { margin:0px; padding:3px;}} .notofont {font-family:"Noto Serif",Cambria,"Palatino Linotype","Book Antiqua","URW Palladio L",serif;;}li.toc{padding-top:5px;}li.toc a{color:#888;}li.toc a:hover{color:white;background:#62a6c8;text-decoration:none;}li.toc a{background:transparent;-webkit-transition:background-color .25s;-moz-transition:background-color .25s;-0-transition:background-color .25s;transition:background-color .25s;margin-left:-3px;padding:1px;}.faq-toc-item-separator {width:20%;border-top:1px solid #ccc;}.faq-toc-item {line-height: 1.3;margin: 3px 0;}.faq-toc-item > a > div {color:#888;font-size: 66%;display: inline-block;}.faq-toc-item > a:hover {text-decoration: none;color:#0086c8;}.faq-toc-item > a {display: inline-block;width: calc(100% - 1em);color:#444;vertical-align: top;}.faq-toc-item::before {content: '≡';color:#0086c8;width: 1em;display: inline-block;}.entry-content {line-height: 1.6em;}.faq-read-more:hover {background: #0086c8;text-decoration: none;}.faq-read-more {border:1px solid #888;background: #aaaaaa;color:white;text-shadow:0px 1px 1px black;border-radius:2px;-moz-border-radius:2px;-webkit-border-radius:2px;padding:5px;font-size:15px;}.faqlisttitle {font-size:28px;padding:3px;}.faqlisttitle:hover {background:#eeeeee;text-decoration: none;}p.bigletter:first-letter {float:left;font-size:4em;margin-right:.06em;line-height:90%;}blockquote {color: #a5a4a4;background: url(https://aqicn.org/images/blockquote.png) no-repeat; margin: 30px;padding: 3px 100px 3px 80px; } @media only screen and (max-width: 800px) { blockquote { margin:0px; padding:10px 0 10px 30px ;background:none;}}code.language-javascript {overflow: scroll;white-space: pre;word-spacing: normal;word-break: normal;display: block;}code.code-snippet-inline {padding:3px 3px 0px 3px;margin: .5em 0;-webkit-box-shadow: 0px 0px 0px 1px #dfdfdf;-moz-box-shadow: 0px 0px 0px 1px #dfdfdf;box-shadow: 0px 0px 0px 1px #dfdfdf;background-color: #fdfdfd;-webkit-border-radius: 0.3em;-moz-border-radius: 0.3em;-ms-border-radius: 0.3em;-o-border-radius: 0.3em;border-radius: 0.3em;color: black;font-family: Consolas, Monaco, 'Andale Mono', monospace;direction: ltr;text-align: left;white-space: pre;overflow: scroll;word-wrap: break-word;word-spacing: normal;color:#c92c2c;}code.code-snippet-inline span.string {color: #2f9c0a;}code.code-example {font-family: Consolas, Monaco, 'Andale Mono', monospace;background-color:#f8f8f8;border:1px solid #888;padding:20px;display:inline-block;margin:20px;font-size:15px;line-height:1.2;text-align:left;-webkit-box-shadow: 0px 0px 0px 1px #dfdfdf;-moz-box-shadow: 0px 0px 0px 1px #dfdfdf;box-shadow: 0px 0px 0px 1px #dfdfdf;background-color: #fdfdfd;-webkit-border-radius: 0.3em;-moz-border-radius: 0.3em;-ms-border-radius: 0.3em;-o-border-radius: 0.3em;border-radius: 0.3em;}</style><div class='h1section'><h1><div id='h1header1' style='padding:2px;padding:5px 0;font-family:"Noto Serif",Cambria,"Palatino Linotype","Book Antiqua","URW Palladio L",serif;;;'>Un guide du débutant sur la qualité de l'air en diffusion instantanée et en diffusion immédiate.</div><div id='h1header2' class='h1sub' >A Beginner's Guide to Air Quality Instant-Cast and Now-Cast. </div></h1></div><script type='text/javascript'> ; if (!isMobileUA) { fitLine('#h1header1',.88,{maxfs:45});fitLine('#h1header2',.88,{maxfs:38}); }; </script><style>.section-outer {text-align: initial;}.section-content {max-width: 95%;width: 1100px;font-size: 18px;min-height: 300px;text-align: initial;margin-top: 10px;margin-bottom: 10px;line-height: 1.8;margin-left: auto;margin-right: auto;}.section-content-tight {min-height: 0px;}.section-content-alt {background-color: #f0f0f0;border-top: 1px solid #ccc;border-bottom: 1px solid #ddd};.section-banner {background-size: 100%;background: url(https://aqicn.org/images//bluesky-banner-panoramic.jpg) no-repeat center bottom #eee;margin-top: -2px;z-index: -1;border-bottom: 1px solid #888;width: 100%;}.h2-title {font-family: inherit;font-size: 1.1em;overflow: hidden;text-align: center;text-transform: capitalize;}.h2-title:before,.h2-title:after {background-color: #ddd;content: '';display: inline-block;height: 1px;position: relative;vertical-align: middle;width: 50%;}.h2-title:before {right: 0.5em;margin-left: -50%;}.h2-title:after {left: 0.5em;margin-right: -50%;}@media only screen and (max-width: 800px) {.section-content {line-height: 1.6;max-width: 98%;min-height: 10px;}.section-banner {display: none;}}</style><div class='whitebody' style='font-family:"Noto Serif",Cambria,"Palatino Linotype","Book Antiqua","URW Palladio L",serif;'><div class='section-outer'><div class='section-content' ><i>Posted on March 15<sup>th</sup> 2015</i><div style='height:1px;background-color:#aaaaaa;width:300px;margin-top:5px;'></div><small><i>(re-edited on January 12<sup>th</sup> 2020)</i></small><br><div id="gtrans-div-id" style="float:right" class="gtrans-div"></div><script>try { googleTranslate(); } catch (e) {}</script><div class='ui-share-btns'><a id='share-facebook' href='https://www.facebook.com/dialog/share?app_id=643196515742584&display=popup&href=https%3A%2F%2Faqicn.org%2Ffaq%2F2015-03-15%2Fair-quality-nowcast-a-beginners-guide%2Ffr%2F&redirect_uri=https%3A%2F%2Faqicn.org%2Ffaq%2F2015-03-15%2Fair-quality-nowcast-a-beginners-guide%2Ffr%2F' class='ui-share-btn' title=''><svg viewBox="0 0 24 24" width=24px height=24px xmlns="http://www.w3.org/2000/svg"><path d="M24 12.073c0-6.627-5.373-12-12-12s-12 5.373-12 12c0 5.99 4.388 10.954 10.125 11.854v-8.385H7.078v-3.47h3.047V9.43c0-3.007 1.792-4.669 4.533-4.669 1.312 0 2.686.235 2.686.235v2.953H15.83c-1.491 0-1.956.925-1.956 1.874v2.25h3.328l-.532 3.47h-2.796v8.385C19.612 23.027 24 18.062 24 12.073z"/></svg></a><script>try{tlite.enable(document.getElementById('share-facebook'),{text:"<div style='font-size:120%'>Share on facebook:<\/div>A Beginner's Guide to Air Quality Instant-Cast and Now-Cast. <br>(https:\/\/aqicn.org\/faq\/2015-03-15\/air-quality-nowcast-a-beginners-guide\/fr\/)"});}catch(e){}</script><a id='share-twitter' href='http://www.twitter.com/share?url=https%3A%2F%2Faqicn.org%2Ffaq%2F2015-03-15%2Fair-quality-nowcast-a-beginners-guide%2Ffr%2F' class='ui-share-btn' title=''><svg version="1.0" xmlns="http://www.w3.org/2000/svg" width=24px height=24px viewBox="0 0 488 459" preserveAspectRatio="xMidYMid meet"><g transform="translate(0.000000,459.000000) scale(0.100000,-0.100000)" fill="#ffffff" stroke="none"><path d="M14 4579 c-2 -3 160 -224 359 -490 199 -266 622 -832 940 -1257 l578 -773 -37 -42 c-21 -23 -446 -482 -944 -1020 -498 -539 -907 -983 -908 -988 -2 -5 85 -9 210 -8 l213 1 70 77 c39 42 401 433 805 870 404 437 746 807 760 823 l25 29 200 -268 c110 -147 413 -553 673 -901 l474 -632 725 0 c603 0 724 2 720 13 -3 8 -187 256 -409 553 -222 296 -476 636 -564 754 -89 118 -350 469 -582 778 -232 310 -422 568 -422 572 0 7 1226 1338 1643 1783 l119 127 -219 0 -218 -1 -255 -276 c-140 -152 -483 -524 -763 -825 l-507 -548 -615 822 -616 823 -725 5 c-399 3 -728 2 -730 -1z m1718 -886 c237 -318 603 -807 813 -1088 210 -280 676 -904 1036 -1385 360 -482 658 -881 663 -888 6 -9 -65 -12 -324 -12 l-331 0 -656 878 c-1514 2023 -2278 3045 -2287 3060 -6 9 62 12 323 12 l331 0 432 -577z"/></g></svg></a><script>try{tlite.enable(document.getElementById('share-twitter'),{text:"<div style='font-size:120%'>Share on twitter:<\/div>A Beginner's Guide to Air Quality Instant-Cast and Now-Cast. <br>(https:\/\/aqicn.org\/faq\/2015-03-15\/air-quality-nowcast-a-beginners-guide\/fr\/)"});}catch(e){}</script><a id='share-reddit' href='https://reddit.com/submit?url=https%3A%2F%2Faqicn.org%2Ffaq%2F2015-03-15%2Fair-quality-nowcast-a-beginners-guide%2Ffr%2F&title=A+Beginner%27s+Guide+to+Air+Quality+Instant-Cast+and+Now-Cast.+' class='ui-share-btn' title=''><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width=24px height=24px version="1.1" viewBox="0 0 256 256" xml:space="preserve"><g style="stroke: none; stroke-width: 0; stroke-dasharray: none; stroke-linecap: butt; stroke-linejoin: miter; stroke-miterlimit: 10; fill: none; fill-rule: nonzero; opacity: 1;" transform="translate(1.4065934065934016 1.4065934065934016) scale(2.81 2.81)" ><circle cx="45" cy="45" r="45" style="stroke: none; stroke-width: 1; stroke-dasharray: none; stroke-linecap: butt; stroke-linejoin: miter; stroke-miterlimit: 10; fill: rgb(255,255,255); fill-rule: nonzero; opacity: 1;" transform=" matrix(1 0 0 1 0 0) "/><path d="M 75.011 45 c -0.134 -3.624 -3.177 -6.454 -6.812 -6.331 c -1.611 0.056 -3.143 0.716 -4.306 1.823 c -5.123 -3.49 -11.141 -5.403 -17.327 -5.537 l 2.919 -14.038 l 9.631 2.025 c 0.268 2.472 2.483 4.262 4.955 3.993 c 2.472 -0.268 4.262 -2.483 3.993 -4.955 s -2.483 -4.262 -4.955 -3.993 c -1.421 0.145 -2.696 0.973 -3.4 2.204 L 48.68 17.987 c -0.749 -0.168 -1.499 0.302 -1.667 1.063 c 0 0.011 0 0.011 0 0.022 l -3.322 15.615 c -6.264 0.101 -12.36 2.025 -17.55 5.537 c -2.64 -2.483 -6.801 -2.36 -9.284 0.291 c -2.483 2.64 -2.36 6.801 0.291 9.284 c 0.515 0.481 1.107 0.895 1.767 1.186 c -0.045 0.66 -0.045 1.32 0 1.98 c 0 10.078 11.745 18.277 26.23 18.277 c 14.485 0 26.23 -8.188 26.23 -18.277 c 0.045 -0.66 0.045 -1.32 0 -1.98 C 73.635 49.855 75.056 47.528 75.011 45 z M 30.011 49.508 c 0 -2.483 2.025 -4.508 4.508 -4.508 c 2.483 0 4.508 2.025 4.508 4.508 s -2.025 4.508 -4.508 4.508 C 32.025 53.993 30.011 51.991 30.011 49.508 z M 56.152 62.058 v -0.179 c -3.199 2.405 -7.114 3.635 -11.119 3.468 c -4.005 0.168 -7.919 -1.063 -11.119 -3.468 c -0.425 -0.515 -0.347 -1.286 0.168 -1.711 c 0.447 -0.369 1.085 -0.369 1.544 0 c 2.707 1.98 6.007 2.987 9.362 2.83 c 3.356 0.179 6.667 -0.783 9.407 -2.74 c 0.492 -0.481 1.297 -0.47 1.779 0.022 C 56.655 60.772 56.644 61.577 56.152 62.058 z M 55.537 54.34 c -0.078 0 -0.145 0 -0.224 0 l 0.034 -0.168 c -2.483 0 -4.508 -2.025 -4.508 -4.508 s 2.025 -4.508 4.508 -4.508 s 4.508 2.025 4.508 4.508 C 59.955 52.148 58.02 54.239 55.537 54.34 z" style="stroke: none; stroke-width: 1; stroke-dasharray: none; stroke-linecap: butt; stroke-linejoin: miter; stroke-miterlimit: 10; fill: #25a1de; fill-rule: nonzero; opacity: 1;" transform=" matrix(1 0 0 1 0 0) " stroke-linecap="round" /></g></svg></a><script>try{tlite.enable(document.getElementById('share-reddit'),{text:"<div style='font-size:120%'>Share on reddit:<\/div>A Beginner's Guide to Air Quality Instant-Cast and Now-Cast. <br>(https:\/\/aqicn.org\/faq\/2015-03-15\/air-quality-nowcast-a-beginners-guide\/fr\/)"});}catch(e){}</script></div><style>.ui-share-btns {display: block;margin: 0;vertical-align: middle;}.ui-share-btns svg {height: 20px;vertical-align: middle;fill: white;}.ui-share-btn {background-color: #25a1de;color: rgba(255, 255, 255, .8);font-size: 15px;line-height: 20px;display: inline-block;text-align: center;border: 1px solid #0086c8;cursor: pointer;border-radius: 4px;padding: 3px 5px;margin: 3px;max-width: 800px;min-width: 30px;}.ui-share-btn:first-child {margin-left: 0px;}.ui-share-btn:hover {background-color: #f8f8f8;border-color: #adadad;text-decoration: none;color: black;}.ui-share-btn:hover svg {fill: black;}.ui-share-btn:hover svg g {fill: black;}.ui-share-btn a:hover {text-decoration: none;}</style><i style='color:#888;font-size:13px;word-break: break-all;'>Partager: <a href='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/fr/'>aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/fr/</a></i><br><div class='entry-content' ng-controller='MainController as ctrl'> <div style='float:right;padding-left:10px;'> <img src='/images/nowcast/typhoon-asia-2004293.jpg' width=468> <center> <small> Typhoon and Dust on East Asia, Courtesy of NASA (<a href='http://alliance.la.asu.edu/mywonderfulworld/GeoLiteracy/WilliamsNature/williamsnature.html'>attribution</a>) </small> </center> <script> if (0) cityShowAd("6885275862", 300, 100); </script> <br> </div> <p>En mars 2015, nous avons eu la chance de rencontrer à Pékin plusieurs spécialistes de l'environnement du Département d'État américain ainsi que de la China Mission ( <i>la célèbre entité qui gère les moniteurs PM <sub>2,5</sub> à l'ambassade américaine de Pékin</i> ).</p> <p>Parmi tous les sujets abordés, il en est un qui mérite d'être évoqué, à savoir le système de « <i><b>nowcast</b></i> ». Ce système est utilisé par l'EPA des États-Unis pour convertir les lectures brutes de polluants, exprimées en µg/m3 ou <i>ppb</i> , en AQI (échelle de 0 à 500). Il est utilisé pour toutes les valeurs AQI signalées sur le site Web <a href='http://airnow.gov'>airnow.gov</a> .</p> <p>Le concept derrière la <i>prévision immédiate</i> est de compenser la « <i>moyenne sur 24 heures</i> », qui doit être utilisée lors de la conversion des concentrations en AQI. La raison de cette moyenne est que l' <a href='http://airnow.gov/index.cfm?action=aqibasics.aqi'>échelle AQI</a> précise que chacun des niveaux de préoccupation pour la santé (c'est-à-dire bon, modéré,... malsain...) est valable sous une exposition de 24 heures <sup><a href="#nowcast-footnote-1">[1]</a></sup> . Par exemple, lorsqu'on voit un AQI de 188 (Malsain), il faut le lire comme " <i style='color:#888;'>si je reste dehors pendant 24 heures et que l'AQI est de 188 <span style='color:#cc0033;'>pendant ces 24 heures</span> , alors l'effet sur la santé est Malsain</i> ". C'est tout à fait différent de dire que « <i style='color:#888;'>si l'IQA rapporté est maintenant de 188, alors l'effet sur la santé est malsain</i> ».</p> <p>Le problème est que la moyenne sur 24 heures est une <b>très mauvaise idée</b> et devrait être abolie <sup><a href="#nowcast-footnote-3">[3]</a></sup> pour au moins ces deux raisons :</p> <ul> <li> <span>Premièrement, la dynamique de la pollution atmosphérique est telle que le vent purifie complètement l’air en moins de 30 minutes !</span> <span>Ce phénomène est fréquemment observé à Pékin avec les forts vents du nord capables de faire passer l'IQA PM <sub>2,5</sub> de plus de 300 à moins de 50 en moins d'une heure <sup><a href="#nowcast-footnote-2">[2]</a></sup> . Lorsque cela se produit, personne ne veut attendre 24 heures avant de savoir que la qualité de l’air est bonne (et sortir se promener pour profiter de l’air frais !)</span> <br> <br> <li> <span>La deuxième raison est lorsque la qualité de l’air se détériore soudainement. Un cas célèbre est celui de l'incendie de forêt indonésien qui provoque le smog de Singapour lorsque les vents se dirigent vers le nord, dans quelles circonstances l'IQA peut passer de moins de 50 à plus de 150 en seulement une heure. En fait, nous avons reçu de nombreuses demandes de personnes asthmatiques/sensibles alors que Singapour ne fournissait encore que des lectures moyennes sur 24 heures.</span> </ul> <p>C'est pour ces raisons que l'EPA des États-Unis a introduit le système <i>de prévision immédiate</i> : il s'agit d'une formule de conversion alternative utilisée pour contrebalancer le besoin d'établir une moyenne dans des conditions changeantes de la qualité de l'air. D'après <a href='http://en.wikipedia.org/wiki/Nowcast_%28Air_Quality_Index%29'>Wikipédia</a> , il est décrit comme suit :</p> <blockquote> <span>Le NowCast est calculé à partir des 12 heures les plus récentes de données de surveillance des particules, mais le NowCast pondère plus fortement les heures de données les plus récentes qu'une moyenne ordinaire sur 12 heures lorsque les niveaux de polluants changent. Le NowCast est utilisé à la place d'une concentration moyenne de particules sur 24 heures dans le calcul de l'IQA jusqu'à ce qu'une journée civile entière de concentrations horaires ait été surveillée.</span> </blockquote> <p>La formule utilisée pour calculer l’AQI <i>NowCast</i> peut sembler barbare pour un non-scientifique.</p> <center style='font-family:"Times New Roman",serif'> <img src='/images/nowcast/nowcast-formula-generalized.png' width=600 style='vertical-align: middle;'> <span style='color:#888'>and </span> <i style='color:#1166c7'>W<sub>min</sub></i> = <sup>1</sup>/<sub>2</sub> <span style='color:#888'>and </span> <i style='color:#1166c7'>N</i> = 12 </center> <br> <p>Mais en réalité, c’est assez simple quand on regarde cet exemple appliqué à la qualité de l’air de Pékin.</p> <style type="text/css"> .axis path, .axis line { fill: none; font-size: 12px; stroke: black; shape-rendering: crispEdges; } .nowcastgraphs { font-size: 15px; border: 1px solid #cccccc; background-color: #f8f8f8; display: inline-block; width: 100%; padding: 10px; text-align: left; color: #888888; margin: 0 0 5px 0; box-sizing: border-box; } </style> <center> <span class='nowcastgraphs'> Instant AQI (no averaging, AQI converted directly from the 1 hour readings): <div id='instantAQI' style='font-size:12px;halign:center;'></div> <br> NowCast AQI: <div id='nowcastAQI' style='font-size:12px;halign:center;'></div> <br> </span> </center> <p>Le résultat de l’IQA calculé pour <i>la prévision immédiate</i> est encore très prononcé en termes de moyenne, du moins bien plus que ce à quoi on pourrait s’attendre en vivant dans la poussière asiatique. L'une des raisons est que le facteur de pondération, utilisé pour déterminer le niveau de changement, a un seuil fixé à un minimum de 0,5, alors qu'en réalité, sa valeur est bien inférieure à 0,5 dans de nombreux cas. Le graphique suivant montre ce facteur de pondération seuil, où le rouge est utilisé pour désigner les poids inférieurs à 0,5.</p> <center> <span class='nowcastgraphs'> NowCast weight factors: <div id='weightfactor' style='font-size:12px;halign:center;'></div> </span> </center> <p>La formule de prévision immédiate, telle qu'elle est définie aujourd'hui, est le fruit de la recherche basée sur les niveaux de qualité de l'air en Amérique. Alors que pour les États-Unis, cela donne un rapport précis sur les conditions actuelles, ce n'est peut-être pas le cas de l'Asie où la dynamique de la qualité de l'air est beaucoup plus forte. Pour cette raison, nous pensons que la formule <i>de prévision immédiate</i> devrait être adaptée à chaque continent.</p> <span>Pour l'Asie, cela pourrait être défini comme</span> <span style='font-family:"Times New Roman",serif'> <i style='color:#1166c7'>W<sub>min</sub></i> = <sup>1</sup>/<sub>10</sub> <span style='color:#888'>and </span> <i style='color:#1166c7'>N</i> = 3 </span>, <span>correspondant au graphique suivant :</span> <center> <span class='nowcastgraphs'> <span>NowCast modifié pour l'Asie (alias NowCast Asia AQI) :</span> <div id='nowcastasiaAQI' style='font-size:12px;halign:center;'></div> <center> <small> <br> <span>Si vous le souhaitez, vous pouvez également modifier directement vous-même les deux paramètres :</span> <span style='font-family:"Times New Roman",serif'> <i style='color:#1166c7'>W<sub>min</sub></i> = <input type='number' value=.1 class='nowcastparams' id='nowcastwmin'> <span style='color:#888'> and </span> <i style='color:#1166c7'>N</i> = <input type='number' value=3 class='nowcastparams' id='nowcastn'> </span> </small> </center> <span>Pour référence, AQI instantané :</span> <div id='instantAQI2' style='font-size:12px;halign:center;'></div> </span> </center> <style type="text/css"> .nowcastparams { padding: 3px; font-size: 18px; text-align: center; width: 50px; } </style> <p>Pour l'instant, la formule de conversion utilisée sur le <a href='/home/fr/'>projet World Air Quality Index</a> ainsi que sur l'AQI de la mission chinoise (alias l'ambassade américaine de Pékin, le consulat américain de Shanghai, etc.) est toujours basée sur l'" <b>Instant AQI</b> ", alias "InstantCast". (c'est-à-dire pas de moyenne du tout). Mais, sur la base des résultats de cette proposition « Asian Nowcast », cela pourrait être mis à jour très prochainement.</p> <script src='/jscripts/d3/d3.min.js?_=20190418.093123&type=script'></script><script src='/jscripts/moment/bundle.min.js?_=20200103.150752&type=script'></script><script src='/air/view/stats/plot.js?_=20190418.093129&type=script'></script><script src='/air/view/stats/nowcast-plot.js?_=20190418.093129&type=script'></script><link href='/air/view/stats/style.css?_=20190418.093129&type=css' rel='stylesheet'/> <script type='text/javascript'></script> <script type='text/javascript'> function calculatePm25Aqi(val) { var c = parseFloat(val); var range = [0, 50, 100, 150, 200, 300, 400, 500]; var scale = [0, 12, 35.5, 55.5, 150.5, 250.5, 350.5, 500.5]; for (var i = 0; i < scale.length - 1; i++) { if (c >= scale[i] && c < scale[i + 1]) { var aqi = range[i] + (c - scale[i]) * (range[i + 1] - range[i]) / (scale[i + 1] - scale[i]); aqi = Math.round(aqi); return aqi; } } return 500; } function instantAQI(val) { return calculatePm25Aqi(val / 1000); } function nowcastAQI(val, p, opt) { var minweight = opt.minweight || .5; var cmin = -1, cmax = -1; p.forEach(function(c) { if (cmin == -1 || cmin > c) cmin = c; if (cmax == -1 || cmax < c) cmax = c; }); var w = Math.max(minweight, cmin / cmax); var v = (val / 1000); var i = 1, div = 1, s = 1; p.forEach(function(c) { s *= w; v += c * s / 1000; div += s; }); v /= div; v = calculatePm25Aqi(v); return Math.round(v); } function weightfactor(val, p) { var cmin = -1, cmax = -1; p.forEach(function(c) { if (cmin == -1 || cmin > c) cmin = c; if (cmax == -1 || cmax < c) cmax = c; }); return Math.round(100 * cmin / cmax) / 100; } function weightcolor(v) { var colors = [ '#ff0000','#cc1b28','#993650','#665078','#336ba0','#0086c8','#0086c8','#339ed3','#66b6de','#99cfe9','#cce7f4','#ffffff',]; return colors[Math.round(v * 10)]; } var beijing = { "cityID": "Beijing", "pol": "pm25", "ndays": "15", "data": [1426316400, 67000, "", -11000, "", -2000, "", 5000, "", 3000, "", 5000, "", 3000, "", 22000, "", 4000, "", -55000, "", 0, "", -7000, "", -7000, "", -15000, "", 4000, "", 2000, "", -9000, "", 8000, "", 4000, "", -4000, "", 9000, "", 14000, "", 78000, "", 37000, "", -25000, "", -4000, "", -15000, "", -1000, "", 13000, "", 11000, "", 12000, "", -21000, "", -14000, "", -27000, "", 2000, "", 4000, "", -15000, "", -16000, "", -13000, "", -16000, "", 12000, "", 5000, "", 16000, "", 23000, "", -8000, "", 11000, "", -4000, "", 3000, "", 6000, "", -1000, "", -10000, "", -2000, "", -7000, "", -1000, "", 4000, "", -1000, "", -21000, "", -11000, "", -5000, "", -6000, "", -10000, "", -5000, "", -3000, "", 3000, "", -3000, "", -1000, "", -3000, "", 5000, "", -10000, "", 11000, "", 14000, "", 0, "", 54000, "", 8000, "", 8000, "", -3000, "", 6000, "", -11000, "", -18000, "", 3000, "", -6000, "", 0, "", -1000, "", -5000, "", -30000, "", -6000, "", 5000, "", 4000, "", -2000, "", -11000, "", -11000, "", 1000, "", -8000, "", 17000, "", 13000, "", -5000, "", -11000, "", -14000, "", -1000, "", -5000, "", 2000, "", 3000, "", 2000, "", -1000, "", 2000, "", -2000, "", 1000, "", -1000, "", 0, "", -3000, "", 3000, "", 3000, "", -1000, "", -2000, "", 1000, "", 1000, "", -2000, "", 7000, "", -9000, "", -4000, "", 1000, "", 1000, "", 0, "", 1000, "", 0, "", 5000, "", -3000, "", 3000, "", 7000, "", -8000, "", 5000, "", -6000, "", -1000, "", 3000, "", -1000, "", 3000, "", -1000, "", 1000, "", 0, "", 113000, "", 112000, "", 8000, "", 11000, "", -18000, "", -24000, "", -11000, "", 20000, "", 5000, "", -11000, -7200, -16000, "", 12000, "", 7000, "", 11000, "", -5000, "", -12000, "", -13000, "", -1000, "", -6000, "", -4000, "", -14000, "", 21000, "", 14000, "", 8000, "", 15000, "", -12000, "", -2000, "", 1000, "", 23000, "", -4000, "", 22000, "", 14000, "", 5000, "", -1000, "", 21000, "", 12000, "", 3000, "", -28000, "", -2000, "", -33000, "", -10000, "", -12000, "", -20000, "", -22000, "", 26000, "", 0, "", -2000, "", -10000, "", -23000, "", -9000, "", -17000, "", 1000, "", 10000, "", -1000, "", 14000, "", 3000, "", 20000, "", -57000, "", -26000, "", 24000, "", 11000, "", 9000, "", -22000, "", -47000, "", -18000, "", -2000, "", 0, "", -3000, "", -8000, "", 3000, "", 28000, "", 4000, "", 65000, "", -18000, "", -10000, "", 1000, "", -2000, "", -15000, "", -7000, "", 21000, "", -9000, "", -13000, "", -15000, "", -20000, "", -15000, "", -5000, "", -13000, "", -4000, "", -7000, "", -10000, "", 2000, "", 0, "", 8000, "", -13000, "", -6000, "", -3000, "", 6000, "", 3000, "", 2000, "", -2000, "", -8000, "", 2000, "", 1000, "", -1000, "", -1000, "", -4000, "", 1000, "", 0, "", 0, "", 3000, "", 3000, "", -2000, "", 1000, "", -1000, "", -5000, "", -1000, "", 1000, "", 1000, "", 3000, "", -5000, "", 0, "", 1000, "", 1000, "", -1000, "", -1000, "", -2000, "", -1000, "", 1000, "", 1000, "", 2000, "", -1000, "", -2000, "", 2000, "", 3000, "", 2000, "", 5000, "", -2000, "", 4000, "", 8000, "", -4000, "", -4000, "", 12000, "", 25000, "", 45000, "", 30000, "", 1000, "", 7000, "", 7000, "", -11000, "", -17000, "", -14000, "", -21000, "", -5000, "", -3000, "", 0, "", -5000, "", -11000, "", -11000, "", 4000, "", -11000, "", -15000, "", -8000, "", -4000, "", 7000, "", 7000, "", -1000, "", -4000, "", 17000, "", 14000, "", 7000, "", 8000, "", -2000, "", -35000, "", -16000, "", -3000, "", 0, "", 9000, "", 23000, "", 71000, "", -63000, "", 71000, "", 85000, "", 12000, "", 7000, "", -3000, "", -7000, "", -6000, "", 2000, "", 21000, "", -19000, "", -5000, "", -24000, "", -15000, "", -49000, "", -19000, "", -9000, "", -20000, "", -13000, "", -10000, "", -8000, "", 5000, "", -5000, "", 2000, "", 4000, "", -1000, "", -10000, "", 0, "", 4000, "", 1000, "", -2000, "", 6000, "", -9000, "", -10000, "", 3000, "", -4000, "", 4000, "", -12000, "", 0, "", 1000, "", -2000, "", -9000, "", 1000, "", -2000, "", 2000, "", 4000, "", -6000, "", 0, "", 4000, "", -1000, "", 5000, "", 2000, "", -3000, "", 0, "", -6000, "", 7000, "", -3000, "", 4000, "", -3000, "", 7000, "", -11000, "", 4000, "", 1000, "", -5000, "", 3000, "", -5000, "", 2000, "", 4000, "", 16000, "", -8000, "", -4000, "", 8000, "", -12000], "utime": "2015-03-14 07:00:00", "step": -3600 }; function initPage() { $('.nowcastparams').bind('input propertychange', function() { var wmin = $("#nowcastwmin").val(); var n = $("#nowcastn").val(); console.log(typeof parseInt(n)); if (typeof parseInt(wmin) == 'number' && typeof parseInt(n) == 'number') { $("#nowcastasiaAQI").html(""); new NowCastGraph("#nowcastasiaAQI").plot(beijing, width, height, nowcastAQI, { minweight: wmin, qlen: n }); } }); var width = document.getElementById("instantAQI").clientWidth - 20; var height = 100; new NowCastGraph("#instantAQI2").plot(beijing, width, 80, instantAQI); new NowCastGraph("#instantAQI").plot(beijing, width, height, instantAQI); new NowCastGraph("#nowcastAQI").plot(beijing, width, height, nowcastAQI, { minweight: .5 }); new NowCastGraph("#weightfactor").plot(beijing, width, 88, weightfactor, { colorf: weightcolor, minv: -.1, maxv: 1 }); new NowCastGraph("#nowcastasiaAQI").plot(beijing, width, height, nowcastAQI, { minweight: .1, qlen: 3 }); } </script> <br> <br> ... <br> <br> <div style='border-top:1px solid black;width:120px;'></div> <small> <div id='nowcast-footnote-1'> <span>[1] La durée de 24 heures est basée sur des décennies d' <a href='http://en.wikipedia.org/wiki/Epidemiology'>études épidémiologiques</a> utilisées pour corréler l'exposition à la pollution de l'air et un risque accru pour la santé. De nouvelles études épidémiologiques sont en cours pour corréler l'effet d' <b>une exposition instantanée</b> (c'est-à-dire une exposition d'environ 1 heure ou moins), mais cela peut prendre plusieurs années avant que leurs résultats puissent être convertis en une nouvelle « échelle AQI instantanée » officielle.</span> </div> <div id='nowcast-footnote-2'> <span>[2] Les vents forts ont assez souvent un effet sur l'augmentation de l'IQA PM <sub>10</sub> en raison de la remise en suspension des poussières.</span> </div> <div id='nowcast-footnote-3'> <span>[3] Au moment de la rédaction de cet article, en mars 2015, de nombreux pays n'offraient encore qu'une moyenne de 24 heures. Aujourd'hui, en septembre 2016, les deux seuls pays connus qui ne fournissent encore qu'une moyenne de 24 heures sont <a href='http://apims.doe.gov.my'>la Malaisie</a> et <a href='http://www.env.gov.bn/'>Brunei</a> . Tous les autres pays fournissent non seulement des données (horaires) partielles, mais également des concentrations individuelles pour chaque polluant.</span> </small> <br> <br> </div></div></div></div><center style='border-top: 1px solid #ccc'><center style='margin:10px 0;'><ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-0281575029452656" data-ad-slot="2455076269" data-ad-format="auto"></ins></center><script>(adsbygoogle = window.adsbygoogle || []).push({});</script><div class='section-content'><a href='/faq/" . srvLang() . "'><span>Cliquez ici pour voir toutes les entrées de la FAQ</span></a><div style='margin-left: 20px;line-heigh:1.5;color:#888;' class='faqmore'><style type='text/css'>.faqmore li a:hover {background: #62a6c8;color: white;text-decoration: none;}.faqmore li a {color: #888;}</style><li><a href='https://aqicn.org/scale/fr/'>AQI Scale: What do the colors and numbers mean?</a></li><li><a href='https://aqicn.org/faq/using-statistical-distances-for-real-time-sensor-networks-validation/fr/'>Using Statistical Distances for Real-time Sensor Networks Validation</a></li><li><a href='https://aqicn.org/faq/2017-01-10/nitrogen-dioxyde-no2-in-our-atmosphere/fr/'>Nitrogen Dioxyde (NO<sub>2</sub>) in our atmosphere</a></li></div><div style='height:1px;background-color:#aaaaaa;width:220px;margin-top:5px;'></div><center><script>var i18nTexts=(i18nTexts||[]);i18nTexts.push({"wa.KqlOlZrllRNJ+7u88XlbL2RQFwo=":"Oups... Quelque chose s'est mal pass\u00e9. Veuillez r\u00e9essayer plus tard.","wa.ds6QyCdIOHG4hhIEHD2rFqI\/WwI=":"Inscrivez-vous \u00e0 notre liste de diffusion mensuelle gratuite et soyez averti lorsque de nouveaux articles sont disponibles.","wa.Xi+TKw0nK3I5533XVrPPC2U4EGA=":"votre email","wa.P6QFTyFPD4Bj2PtEU75l1GDj4ww=":"soumettre","wa.FoXcvD6sGbwj\/zOhqhL39XuXQsA=":"Veuillez patienter pendant l'enregistrement de votre email"})</script><script src='/webapp/dist/mailing-dyn.740fe2cfc24722505254.js?_=1706407958' type='text/javascript'></script></center><div id='ntf-body-first' style='display:none;'></div><script>function ntfConf() {return {page: "faq",divId: "ntf-body-first"}}</script></div></center><a name="infoaqi"></a><div class='h1section h1section-divider'><div class='h1section-rainbow'><div></div><div></div><div></div><div></div><div></div></div><h1><div id='h1header3' style='padding:2px;font-family:"Noto Serif",Cambria,"Palatino Linotype","Book Antiqua","URW Palladio L",serif;;'>À propos de la qualité de l'air et des mesures de la pollution atmosphérique :</div></h1></div><script type='text/javascript'> ; if (!isMobileUA) { fitLine('#h1header3',.88,{maxfs:45}); }; </script><div class='whitebody' style='font-family:"Noto Serif",Cambria,"Palatino Linotype","Book Antiqua","URW Palladio L",serif;'><div class='section-outer'><div class='section-content' ><center>À propos des niveaux de qualité de l'air<br><br><style type="text/css">#legend-full table.infoaqitable {line-height: 1.5;background-color: white;max-width: 1000px;width: 95%;margin: 0px;border: 1px solid black;cursor: pointer;}#legend-full table.infoaqitable td {padding: 5px;font-size: 15px;text-shadow: none;}#legend-full .aqiwtxt {color: #ffffff;}#legend-full .aqibtxt {color: #000000;}@media only screen and (max-width: 800px) {#legend-full table.infoaqitable {width: 98%;}}@media only screen and (max-width: 800px) {#legend-full table.infoaqitable td {display: block;}#legend-full table.infoaqitable td:nth-child(1) {display: inline-block;font-size: 1.2em;}#legend-full table.infoaqitable td:nth-child(2) {display: inline-block;font-weight: 800;font-size: 1.2em;}}</style><div id='legend-full' onclick='window.location="/scale/"'><table class="infoaqitable"><thead><tr><td>IQA</td><td>Niveau de pollution de l'air </td><td>Impact sur la santé</td></tr></thead><tr style="background-color:#009966;color:white"><td nowrap="true">0 - 50</td><td>Bon</td><td>La qualité de l'air est jugée satisfaisante, et la pollution de l'air pose peu ou pas de risque.</td></tr><tr style="background-color:#ffde33"><td nowrap="true">51 -100</td><td>Modéré</td><td>La qualité de l'air est acceptable. Cependant, pour certains polluants, il peut y avoir un risque sur la santé pour un très petit nombre de personnes inhabituellement sensibles à la pollution atmosphérique.</td></tr><tr style="background-color:#ff9933;color:white"><td nowrap="true">101-150</td><td>Mauvais pour les groupes sensibles</td><td>La qualité de l'air est acceptable; Cependant, pour certains polluants, il peut y avoir un problème de santé modérée pour un très petit nombre de personnes qui sont particulièrement sensibles à la pollution de l'air. </td></tr><tr style="background-color:#cc0033;color:white"><td nowrap="true">151-200</td><td>Mauvais</td><td>Tout le monde peut commencer à ressentir des effets sur la santé; les membres des groupes sensibles peuvent ressentir des effets de santé plus graves.</td></tr><tr style="background-color:#660099;color:white"><td nowrap="true">201-300</td><td>Très mauvais</td><td>Avertissements de santé de conditions d'urgence. Toute la population est plus susceptible d'être affecté. </td></tr><tr style="background-color:#7e0023;color:white"><td nowrap="true">300+</td><td>Dangereux</td><td>Alerte de santé: tout le monde peut ressentir des effets de santé plus graves.</td></tr></table></div><br>Pour en savoir plus sur la qualité de l'air, consultez le <a href='http://en.wikipedia.org/wiki/Air_quality'> sujet Qualité de l'air sur Wikipedia </a> ou <a href='http://www.airnow.gov/index.cfm?action=aqibasics.aqi'> le guide AirNow de la qualité de l'air et de votre santé </a>.<br><br>Pour des conseils de santé très utiles du Dr. Richard Saint Cyr, consultez le blog <a href='http://www.myhealthbeijing.com/'>myhealthbeijing.com</a>.<br><br></center></div></div></div><center><br><ins class="adsbygoogle" style="display:block"data-ad-client="ca-pub-0281575029452656"data-ad-slot="2455076269"data-ad-format="auto"></ins><script>(adsbygoogle = window.adsbygoogle || []).push({});</script><style type='text/css'>.usage-notice {line-height:1.5;max-width:95%;width:1000px;margin-top:10px;padding:5px;font-size: 15px;background-color:#ffffff;text-shadow: 1px 1px 1px white;-webkit-box-shadow: 1px 1px 8px -3px rgba(0,0,0,0.3);}</style><div class="textshadowwhite usage-notice" style=''><b>Notice d'utilisation</b>: Toutes les données sur la qualité de l'air ne sont pas validées au moment de la publication et, pour des raisons d'assurance de la qualité, ces données peuvent être modifiées à tout moment et sans préavis. Le projet <a href='https://aqicn.org'> Indice de la qualité de l'air dans le monde </a> a exercé toutes les compétences et l'attention réalisables dans la compilation du contenu de ces informations. <a href='https://aqicn.org'> Indice de la qualité de l’air dans le monde </a>, l’équipe de projet ou ses agents ne peuvent être tenus responsables, contractuellement, judiciairement ou autrement, de toute perte, blessure ou préjudice résultant directement ou indirectement de la fourniture de ces données.</div><br><br><br></center><style type="text/css">@media print {#fixed-menubar,#footer-overlay {display: none}}.footer {background: #138fcc;background-attachment: fixed;background-image: url("https://aqicn.org/images-static/bluesky-banner-panoramic-dark.jpg");background-position: top center, bottom center;background-size: auto 100%;position: relative;text-align: center;font-weight: normal;margin: 0 auto;color: white;width: 100%;font-family: "Noto Serif", Cambria, "Palatino Linotype", "Book Antiqua", "URW Palladio L", serif;}#fixed-menubar {font-family: "Noto Serif", Cambria, "Palatino Linotype", "Book Antiqua", "URW Palladio L", serif;}#fixed-footer-marker {height: 1px;bottom: 0;position: fixed;}#footer-menu {padding-top: 5px;}#fixed-footer {box-shadow: 0 -1px 1px rgba(0, 0, 0, 0.6);-moz-box-shadow: 0 1px -1px rgba(0, 0, 0, 0.6);-webkit-box-shadow: 0 1px -1px rgba(0, 0, 0, 0.6);}#footer-overlay {box-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);-moz-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);-webkit-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.6);background: #0086c8;}.floating-footer-overlay {bottom: 0px;padding: 0px;margin: 0px;z-index: 1000;position: fixed;display: none;}.footer-logo {box-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);-moz-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);-webkit-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);}.footerattributions {margin-top: 20px;width: 95%;max-width: 1100px;font-size: 15px;}.footercolumnout {width: 95%;max-width: 1100px;font-size: 15px;}.footercolumn {float: left;padding: 0px;margin: 0px;border: 0;text-align: left;padding: 0 10px;}.footercolumn1 {width: 37%;}.footercolumn2 {width: 38%;border-left: 1px dashed white;}.footercolumn3 {width: 15%;border-left: 1px dashed white;}.madeinbjlogo {padding-top: 20px;}@media only screen and (max-width: 920px) {.footercolumn2 {display: none;}}@media only screen and (max-width: 920px) {.footercolumn1 {width: 66%;}.footercolumn3 {width: 20%;}}@media only screen and (max-width: 800px) {.footercolumn {text-align: center;}.footercolumn1 {width: 95%;}.footercolumn3 {width: 95%;border: 0;padding: 10px;text-align: center;float: right;margin: 10px;}.madeinbjlogo {padding-top: 0;}}@media only screen and (max-width: 800px) {}.footercolumn2 li {margin-bottom: 8px;}.footer li a {background: transparent;-webkit-transition: background-color .25s;-moz-transition: background-color .25s;-0-transition: background-color .25s;transition: background-color .25s;margin-left: -8px;-webkit-border-radius: 4px;-moz-border-radius: 4px;-o-border-radius: 4px;border-radius: 4px;padding: 2px 0 2px 8px;text-decoration: none;margin-right: 8px;text-shadow: #000 1px 1px 1px;font-weight: normal !important;}.footer li a:hover {background: #62a6c8}.footer h3 {font-variant: small-caps;font-size: 150%;padding: 0px;margin: 0px;text-shadow: #2d3033 0 1px 0;font-weight: normal !important;margin-right: 8px;}.footer h3 a {font-weight: normal !important;-webkit-transition: background-color .25s;-moz-transition: background-color .25s;-0-transition: background-color .25s;transition: background-color .25s;-webkit-border-radius: 4px;-moz-border-radius: 4px;-o-border-radius: 4px;border-radius: 4px;display: block;.footer h3 a:hover {background: #62a6c8}</style><div id="fixed-footer-marker" class="locked"></div><div id="floating-footer" class="footer-overlay floating-footer-overlay footer"></div><div id="fixed-footer" class="footer"><div id="footer-overlay" class="footer-overlay"></div><br><br><center><div id='fixed-footer-menu-buttons-with-text' style='max-width:80%;margin-bottom:20px;display:none;'><a href='javascript:go2home();' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-home'></div>accueil</div></a> <a href='/here/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-geofencing'></div>ici</div></a> <a href='/map/world/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-globe'></div>carte</div></a> <a href='/mask/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-dustmask'></div>masque!</div></a> <a href='/faq/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-faq'></div>Questions et Reponses</div></a> <a href='/city/all/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-search'></div>rechercher</div></a> <a href='/contact/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-talk'></div>contact</div></a> <a href='/links/fr/' class='menubar-text'><div class='fixed-menubar-button'><div class='sprite-isprt-web-link'></div>liens</div></a> </div><div class='footercolumnout'><div class='footercolumn1 footercolumn'><h3>À propos de ce projet</h3><br><li><a href='/contact/fr/'>Contacter L'équipe De La Qualité De L'Air Mondiale</a></li><li><a href='/media/fr/'>Kit Presse Et Médias</a></li><br><h3><a href='/research/fr/'>Recherches sur la qualité de l'air</a></h3><br><li><a href='/faq/fr/'>Articles Sur La Qualité De L'air</a></li><li><a href='/research/fr/'>Expérimentation sur la qualité de l'air</a></li><li><a href='/sensor/fr/'>Analyse Des Capteurs De La Qualité De L'air</a></li><br><h3><a href='/faq/fr/'>Foire aux questions</a></h3><br><li><a href='/sources/fr/'>Source des données sur la qualité de l'air</a></li><li><a href='/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/fr/'>Calcul De L'indice De La Qualité De L'air</a></li><li><a href='/forecast/fr/'>Prévisions De La Qualité De L'air</a></li><li><a href='/products/fr/'>Equipements Pour La Pollution De L'air (masques, Appareils De Mesure ...)</a></li><li><a href='/api/fr/'>API (interface de programmation d'applications)</a></li><li><a href='/data-platform/fr/'>Plateforme de données historiques</a></li></div><div class='footercolumn2 footercolumn'><h3>Credits</h3><br><li><a href='/sources/fr/'>Toute l'EPA du monde pour son excellent travail de maintien, de mesure et de fourniture d'informations sur la qualité de l'air aux citoyens du monde.</a></li><li><a href='http://www.maxmind.com' target=_>Ce produit comprend des données GeoLite2 créées par MaxMind, disponibles sur maxmind.com.</a><li><a href='http://geonames.org' target=_>Ce produit comprend des informations sur les villes GeoNames, disponibles sur geonames.org.</a><li><a href="http://openweathermap.org/" target="__s">Carte météo ouverte, combinée à l'algorithme d'amélioration qweather™</a><li><a href='http://wxqa.com' target="__s">Programme citoyen d’observateurs météorologiques</a> via <a href='https://cwop.waqi.info' target="__s">cwop.waqi.info</a><li><a href="http://atmosphere.copernicus.eu/" target="__s">Contient des informations modifiées sur le service de surveillance de l'atmosphère Copernicus.</a><li><a href="https://www.flaticon.com/" target="__s" title="Flaticon">Certaines des icônes réalisées par Freepik sur www.flaticon.com</a><li><a href="https://locationiq.com/" target="__s" title="location IQ">Géocodage inversé par locationiq.com</a><li><a href="https://www.openstreetmap.org/copyright" target="__s" title="Open Street Map">Carte de base et données d'OpenStreetMap.</a></div><div class='footercolumn3 footercolumn'><center>© 2008-2024<br><a href='https://waqi.info'><span>Le projet de l'indice mondial de la qualité de l'air</span></a><br><br><img src='https://waqi.info/icons/logo.png?_=1732492958' class='footer-logo' alt='the World Air Quality Index project logo' border=0 height=100>  <img class='async-img' data-src='https://aqicn.org/images/MadeInBJ.png?_=1732492958' class='madeinbjlogo' alt='made in 北京' border=0><br><br></center></div></div></center><div style='clear:both'></div><div style='clear:both;'></div><center><div id='xatzcaqd'></center><br><div id='mailing-list-footer'><style type="text/css">#mailing-list-footer .mailing-list-subscription {text-shadow: #000 1px 1px 1px;font-size: 15px;color: white;}</style><script>var i18nTexts=(i18nTexts||[]);i18nTexts.push({"wa.KqlOlZrllRNJ+7u88XlbL2RQFwo=":"Oups... Quelque chose s'est mal pass\u00e9. Veuillez r\u00e9essayer plus tard.","wa.ds6QyCdIOHG4hhIEHD2rFqI\/WwI=":"Inscrivez-vous \u00e0 notre liste de diffusion mensuelle gratuite et soyez averti lorsque de nouveaux articles sont disponibles.","wa.Xi+TKw0nK3I5533XVrPPC2U4EGA=":"votre email","wa.P6QFTyFPD4Bj2PtEU75l1GDj4ww=":"soumettre","wa.FoXcvD6sGbwj\/zOhqhL39XuXQsA=":"Veuillez patienter pendant l'enregistrement de votre email"})</script><script src='/webapp/dist/mailing-dyn.740fe2cfc24722505254.js?_=1706407958' type='text/javascript'></script></div><center style='clear:both;'><br><small>This page has been generated on Monday, Nov 25th 2024, 08:02 am CST from jp2n</small><br><small><span id='gentime'></span></small><br><br></center><br><br></div><script type="text/javascript">var CFooter = function() {var hasSlider = false;try {var p = window.location.pathname.split("/")[1];hasSlider = ["station", "gaia", "here", "map"].indexOf(p) >= 0;} catch (e) {};var menubar = document.getElementById("fixed-menubar");var _isFloating = true;var slideDY = 35;this.isFloating = function() {if (isMobileUA) return true;return _isFloating;};function checkPosition() {var clientHeight = document.body.clientHeight;var floatingFooterTop = 0;var ff_el = document.getElementById("floating-footer");var ff_el_height = ff_el ? ff_el.clientHeight : 0;do {floatingFooterTop += ff_el.offsetTop ? el.offsetTop : 0;} while (ff_el = ff_el.offsetParent);var fixedFooterTop = 0;var fo_el = document.getElementById("footer-overlay");do {fixedFooterTop += fo_el.offsetTop ? fo_el.offsetTop : 0;} while (fo_el = fo_el.offsetParent);var scrollTop = 0;var b_el = document.body;do {scrollTop += b_el.scrollTop ? b_el.scrollTop : 0;} while (b_el = b_el.parentNode);var screenHeight = 0;var ffm_el = document.getElementById("fixed-footer-marker");do {screenHeight += ffm_el.offsetTop ? ffm_el.offsetTop : 0;} while (ffm_el = ffm_el.offsetParent);if (hasSlider && scrollTop < slideDY) {menubar.style.bottom = -(slideDY - scrollTop) + "px";menubar.style.display = "";_isFloating = true;} else if (screenHeight + scrollTop - ff_el_height >= fixedFooterTop + 40) {menubar.style.display = "none";_isFloating = false;} else {menubar.style.bottom = "0px";menubar.style.display = "";_isFloating = true;}};function init() {var footerOverlay = document.getElementById("footer-overlay");footerOverlay.innerHTML = menubar.innerHTML;footerOverlay.style.display = "";if (!hasSlider) {checkPosition();return;}var st = Date.now();var sdt = 500;var mdt = 500;var timer = setInterval(function() {var dt = Date.now() - st;if (dt < sdt) return;dt -= sdt;dt = dt * dt / mdt;var dy = Math.min(dt, mdt) * slideDY / mdt;menubar.style.bottom = -dy + "px";if (dt > mdt + sdt) {clearInterval(timer);checkPosition();}}, 25);}window.onscroll = function() {checkPosition();};init();return this;};var footer = new CFooter();function initFooter() {};</script><style>.onoffswitch {position: relative; width: 70px;-webkit-user-select:none; -moz-user-select:none; -ms-user-select: none;}.onoffswitch-checkbox {display: none;}.onoffswitch-label {display: block; overflow: hidden; cursor: pointer;border: 2px solid #004E74; border-radius: 20px;}.onoffswitch-inner {display: block; width: 200%; margin-left: -100%;transition: margin 0.3s ease-in 0s;}.onoffswitch-inner:before, .onoffswitch-inner:after {display: block; float: left; width: 50%; height: 30px; padding: 0; line-height: 30px;font-size: 14px; color: white; font-family: Trebuchet, Arial, sans-serif; font-weight: bold;box-sizing: border-box;}.onoffswitch-inner:before {content: "°C";padding-left: 10px;background-color: #04ADFF; color: #FFFFFF;}.onoffswitch-inner:after {content: "°F";padding-right: 10px;background-color: #04ADFF; color: #FFFFFF;text-align: right;}.onoffswitch-switch {display: block; width: 28px; margin: 1px;background: #FFFFFF;position: absolute; top: 0; bottom: 0;right: 36px;border: 2px solid #004E74; border-radius: 20px;transition: all 0.3s ease-in 0s; }.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-inner {margin-left: 0;}.onoffswitch-checkbox:checked + .onoffswitch-label .onoffswitch-switch {right: 0px; }</style><style>#settingsdiv-copy {margin:20px;}#settingsdiv-outer {padding-bottom:10px;position:fixed;z-index: 100003;}#settingsdiv {xdisplay: none;xwidth:200px;xheight:120px;overflow-y: scroll;max-height: 300px;font-size:15px; padding:2px 10px;background-color:#0086c8;-webkit-box-shadow: 1px 1px 2px 0 rgba(0,0,0,0.5);border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px;border:3px solid #fff;color:#fff;}#settingsdiv h2 { font-size:20px; }#settings-lang {padding: 5px;}#settings-lang a:hover {text-decoration: none;}#settings-lang .item:hover {background-color: #eee;color: black;}#settings-lang .item:hover .name {color: black;}#settings-lang .item {max-width: 450px;padding: 2px;}#settings-lang .name span {font-size: 16px;}#settings-lang .name {font-size:18px;color: white;font-variant: small-caps;}#settings-lang .flag {vertical-align: text-bottom;display:inline-block;}#settings-lang select {font-size: 18px;}</style><div id='settingsdiv-outer'><div id='settingsdiv' ><div onclick='settingsMenu.close()' style='cursor:pointer;border-bottom:1px solid #ccccf8;padding-top:12px;'><svg height="24px" viewBox="0 0 512 512" width="24px" style='float:right;fill:white;'><path d="M74.966,437.013c-99.97-99.97-99.97-262.065,0-362.037c100.002-99.97,262.066-99.97,362.067,0 c99.971,99.971,99.971,262.067,0,362.037C337.032,536.998,174.968,536.998,74.966,437.013z M391.782,120.227 c-75.001-74.985-196.564-74.985-271.534,0c-75.001,74.985-75.001,196.55,0,271.535c74.97,74.986,196.533,74.986,271.534,0 C466.754,316.775,466.754,195.212,391.782,120.227z M188.124,369.137l-45.251-45.266l67.876-67.877l-67.876-67.876l45.251-45.267 L256,210.743l67.877-67.892l45.25,45.267l-67.876,67.876l67.876,67.877l-45.25,45.266L256,301.245L188.124,369.137z"/></svg><h2>Paramètres</h2></div><br><center><div id='settings-lang'>Choix de la langue : <br><div class='sprite-isprt-web-gb flag'></div><div class='sprite-isprt-web-cn flag'></div><div class='sprite-isprt-web-jp flag'></div><div class='sprite-isprt-web-kr flag'></div><div class='sprite-isprt-web-pl flag'></div><br><select onchange='location.href = this.value'><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide/' >English - Anglais</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cn' >简体中文 - Chinois</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//jp' >日本 - Japonais</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//es' >español - Francais</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//kr' >한국의 - Coréen</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ru' >русский - Russe</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hk' >繁體中文 - Cantonais</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fr' selected>Francais</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pl' >Polski - Polish</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//de' >Deutsch - German</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//pt' >Português - Portuguese</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//vn' >Tiếng Việt - Vietnamese</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//it' >Italiano - Italian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//id' >bahasa Indonesia - Indonesian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//nl' >Nederlands - Dutch</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//fa' >فارسی - Persian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//th' >ภาษาไทย - Thai</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hu' >Magyar - Hungarian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//el' >Ελληνικά - Greek</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ro' >Română - Romanian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bg' >български - Bulgarian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ur' >اردو - Urdu</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hi' >हिंदी - Hindi</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//ar' >العربية - Arabic</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//sr' >Српски - Serbian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bn' >বাংলা - Bangla</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//bs' >босански - Bosnian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//hr' >hrvatski - Croatian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//tr' >Türkçe - Turkish</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//uk' >українська - Ukrainian</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//cs' >čeština - Czech</option><option value='https://aqicn.org/faq/2015-03-15/air-quality-nowcast-a-beginners-guide//be' >беларускі - Belarusian</option></select></div><br><table><tr><td><center><i>Temperature unit:</i><br><span style='font-size:18px'><span style='display:;' id='settings-temp-label-on'>Celcius</span><span style='display:none;' id='settings-temp-label-off'>Fahrenheit</span></span></center></td><td><div class="onoffswitch" onclick='settingsMenu.click("temp")'><input type="checkbox" name="onoffswitch" class="onoffswitch-checkbox" id="settings-temp" checked ><label class="onoffswitch-label" for="myonoffswitch"><span class="onoffswitch-inner"></span><span class="onoffswitch-switch"></span></label></div></table></center><br></div><div style='display:none;height:0px;' id='settingsdiv-arrow'><div style='width: 0; height: 0; border: 7px solid transparent;top:0px;border-top: 7px solid #fff;position:relative;;margin-left:100px;'></div></div></div><script>function CSettingsMenu(){var self=this;var isInit = false;var timeout = null;var isPopup = false;this.show = function(){log("show!");if (isPopup) {this.close();return;}isPopup = true;$("#settingsdiv-arrow").hide();$("#settingsdiv").show();var pos = $("#footer-settings-img").offset();$("#settingsdiv-outer").css({left: "0px",width: "100%",bottom: "30px"});$("#settingsdiv").css({width: "100%",textAlign: "center",boxSizing: "border-box"});};this.close = function() {log("close!");$("#settingsdiv").hide();isPopup = false;};this.onmouseover = function(){if (isPopup) return;if (!footer || !footer.isFloating()) return;if (getWindowWidth()<800) return;if (!isInit) {$('#settingsdiv-outer').show().mouseleave(function(){ self.onmouseout(); }).mouseenter(function(){ self.onmouseover(); });display("temp");isInit = true;}if (timeout) clearTimeout(timeout);timeout = null;var pos = $("#footer-settings-img").offset();var px = (pos.left+6-100);$("#settingsdiv-outer").css({left: px + "px",bottom: (30) + "px"});$("#settingsdiv").show();$("#settingsdiv-arrow").delay(150).show();var tb = document.getElementById("settingsdiv").getBoundingClientRect(), w =getWindowWidth();var ml = Math.min((w-tb.right-2),0);$("#settingsdiv-outer").css({left:(px+ml)+"px"});};this.onmouseout = function(){if (isPopup) return;isShown = false;if (timeout) clearTimeout(timeout);timeout = setTimeout(function(){$("#settingsdiv").slideUp(200);$("#settingsdiv-arrow").hide();},150);};this.click = function(item){var status = store.get('aqicn-settings-'+item);store.set('aqicn-settings-'+item,status==1?2:1);display(item);if (item=="temp") convertTemperature();};this.val = function(item) {var status = store.get('aqicn-settings-'+item);return status!=1;};var display = function(item) {var status = store.get('aqicn-settings-'+item);if (status==1){$("#settings-"+item+"-label-off").show();$("#settings-"+item+"-label-on").hide();}else{$("#settings-"+item+"-label-on").show();$("#settings-"+item+"-label-off").hide();}var o = document.getElementById("settings-"+item);if (o) o.checked = status!=1;};document.getElementById('settingsdiv-outer').addEventListener('touchmove', function(e) {e.preventDefault();}, false);return this;}var settingsMenu = new CSettingsMenu();</script><script type="text/javascript"> fitLine(".link",.9); </script><script src='https://aqicn.org/air-cache/jquery-3.4.1.min.js?_=20191127.152416' type='text/javascript'></script><script type="text/javascript">function initTime(){if (isMobileUA) return;function setTimeText(){var monthNames = [ "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ]; var dayNames= ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];var newDate = new Date();newDate.setDate(newDate.getDate());var od = document.getElementById("ClockTime");if (od) od.innerHTML = dayNames[newDate.getDay()] + " " + monthNames[newDate.getMonth()] + ' ' + newDate.getDate() + ', ' + newDate.getFullYear();var minutes = new Date().getMinutes();var hours = new Date().getHours();var time = ( hours < 10 ? "0" : "" ) + hours;time += ":"+( minutes < 10 ? "0" : "" ) + minutes;var ot = document.getElementById("ClockTime");if (ot) ot.innerHTML = time;}setInterval( function() { setTimeText() }, 1000*60*15 );setTimeText();};aqi18n.register('aqi-implication-0-50',"La qualit\u00e9 de l'air est jug\u00e9e satisfaisante et la pollution de l'air ne pose peu ou pas de risque");aqi18n.register('aqi-level-0-50',"Bien");aqi18n.register('aqi-implication-50-100',"La qualit\u00e9 de l'air est acceptable. Cependant, pour certains polluants, il peut y avoir un risque sur la sant\u00e9 pour un tr\u00e8s petit nombre de personnes inhabituellement sensibles \u00e0 la pollution atmosph\u00e9rique.");aqi18n.register('aqi-level-50-100',"Mod\u00e9r\u00e9");aqi18n.register('aqi-implication-100-150',"Les membres appartenant \u00e0 des groupes sensibles peuvent ressentir des effets sur leur sant\u00e9. Le reste de la population ne ressentira probablement aucun effet.");aqi18n.register('aqi-level-100-150',"Malsain pour les groupes sensibles");aqi18n.register('aqi-level-100-150-html',"<div style='font-size:66%'>Malsain pour les groupes sensibles<\/div>");aqi18n.register('aqi-implication-150-200',"Tout le monde peut commencer \u00e0 ressentir des effets sur la sant\u00e9; les membres de groupes sensibles peuvent ressentir des effets plus graves sur la sant\u00e9");aqi18n.register('aqi-level-150-200',"Mauvais pour la sant\u00e9");aqi18n.register('aqi-level-150-200-html',"<div style='font-size:66%'>Mauvais pour la sant\u00e9<\/div>");aqi18n.register('aqi-implication-200-300',"Avertissements de sant\u00e9 relatifs aux conditions d'urgence. Toute la population est susceptible d'\u00eatre touch\u00e9e.");aqi18n.register('aqi-level-200-300',"Tr\u00e8s malsain");aqi18n.register('aqi-implication-300-500',"Alerte sant\u00e9: Potentiels effets sur la sant\u00e9 concernant toute la population");aqi18n.register('aqi-level-300-500',"Dangereux");aqi18n.register('updated',"Mise \u00e0 jour");</script><script type="text/javascript">["initFooter","preInitPage","initTime"].forEach(function(f){if (window[f]) { try { window[f](); } catch (e) { loge("error in "+f,e); }} });</script><script src='/jscripts/moment/bundle.min.js?_=20200103.150752&type=script'></script><script src='https://aqicn.org/air-cache/tingle/0.15.1/tingle.min.js?_=20191109.130307' type='text/javascript'></script><script type="text/javascript">document.addEventListener("DOMContentLoaded", function() { ["Page","HeadSearch","Search","Notify","Geolocate","AqiForecast","Download","Sharing","Page2"].forEach(function(f){f = "init"+f;if (window[f]) { try { window[f](); } catch (e) { loge ("error in "+f,e,e.stack);}; }});if (typeof ntfOnInit != "undefined") ntfOnInit();});</script><style type="text/css">.uv-icon.uv-top-right { position:absolute!important;top:38px!important;z-index: 1!important; }.uv-icon.uv-bottom-right { bottom:42px!important;}._hj-f5b2a1eb-9b07_widget { z-index: 0!important; }#uvTab { z-index: 100!important; }.uv-icon { z-index: 100; }</style><script type="text/javascript">(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');ga('create', 'UA-28507883-1', 'auto');ga('send', 'pageview');try {var images = document.querySelectorAll('.async-img');var config = { rootMargin: '50px 0px', threshold: 0.01};function preloadImage(img) {img.src = img.dataset.src; }function onIntersection(entries) {entries.forEach(function(entry) {if (entry.intersectionRatio > 0) {observer.unobserve(entry.target);preloadImage(entry.target);}})}var observer = new IntersectionObserver(onIntersection, config);images.forEach(function(image){observer.observe(image)});} catch (e) {} </script></body></html>