CINXE.COM

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml" > <head> <title>Air Quality Ontario</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <meta name="language" content="english" /> <link rel="sitemap" type="application/xml" title="Sitemap" href="/sitemap/sitemap.xml" />  <meta name="dc.title" content="" /> <meta name="dc.description" content="" /> <meta name="description" content="" /> <meta name="dcterms.audience" content="" /> <meta name="dc.identifier" scheme="URI" content="" /> <meta name="dc.date.created" scheme="W3CDTF" content="" /> <meta name="dc.date.issued" scheme="W3CDTF" content="" /> <meta name="dc.date.modified" scheme="W3CDTF" content="" />   <meta name="dc.subject" scheme="gccore" content="" /> <meta name="Keywords" content="" /> <meta name="dc.type" scheme="oncatype" content="" />   <meta name="dc.format" scheme="IMT" content="text/html" /> <meta name="dc.creator" content="Government of Ontario, Ministry of the Environment" /> <meta name="dc.publisher" content="Government of Ontario, Ministry of the Environment" /> <meta name="dc.contributor" content="Government of Ontario, Ministry of the Environment" /> <meta name="dc.language" scheme="ISO639-2" content="Eng" /> <meta name="dc.coverage.jurisdiction" content="Province of Ontario" /> <meta name="dc.coverage.spatial" content="Ontario, Canada" /> <meta name="dc.rights.intellectualProperty" content="Copyright: Queen's Printer for Ontario, 2025" /> <meta name="go.contact.content" content="" /> <meta name="go.contact.technical" content="" />   <link rel="stylesheet" href="/stylesheets/new.css" type="text/css" media="screen" /> <link rel="stylesheet" href="/stylesheets/master.css" type="text/css" media="screen" /> <link rel="stylesheet" href="/stylesheets/changeme.css" type="text/css" media="screen" /> <link rel="stylesheet" href="/stylesheets/print.css" type="text/css" media="print" /> <link rel="stylesheet" href="/stylesheets/mobile.css" type="text/css" media="handheld" /> <link rel="icon" type="image/png" href="/images/trillium4.ico" /> <link rel="stylesheet" href="/stylesheets/airquality2016.css?v=1" type="text/css" media="screen" />  <script type="text/javascript" src="/scripts/scripts_2015.js"></script> </head> <body id="home"> <div id="skip-link"> <a href="#top" class="element-invisible element-focusable">Skip to main content</a> </div> <div id="wrapper"> <div id="header">  <script type="text/javascript" src="/js/moe_header.js"></script>  <div class="clearfix" id="breadcrumbs" > <ul class="navigation-breadcrumbs" > <li><a href="/">Air Quality Ontario</a></li> </ul> </div> <div id="warning-message" style="padding-top:10px;padding-bottom:5px;display:none;"> <center><strong><h1 style="font-size:18px;color:black;">Notice: Scheduled Network Maintenance</h1><h2 style="font-size:13px;color:black;">A planned maintenance is scheduled for Tuesday, February 18 at 8 pm EST until Wednesday, February 19 at 4 pm. Air quality data will not be updated during this time. In the interim, please visit <a href="https://weather.gc.ca"">weather.gc.ca</a> for current AQHI values provided on an hourly basis. We appreciate your patience and apologize for any inconvenience this may cause.</h2></strong></center> </div> <script> var startDate = new Date('2025-02-18T18:00:00.000'); var endDate = new Date('2025-02-19T16:00:00.000'); var nowDate = new Date(); if (nowDate >= startDate && nowDate <= endDate) { document.getElementById("warning-message").style["display"]="initial"; }</script> </div> <a name="top" id="top"></a> <div id="right_column"> <div class="row"> <h1 style="padding-top:16px" >Air Quality Ontario</h1> </div> <p>The quality of our air directly impacts our health and the natural environment, so we want our air to be as clean as possible. The Ministry of the Environment, Conservation and Parks works to protect and improve air quality through legislation, targeted programs, and partnerships with other jurisdictions.</p> <p>The Ministry has a network of 38 ambient (outside) air monitoring stations across the province that collect real-time air pollution data. This information is communicated to the public through Ontario's new Air Quality Health Index (AQHI) and as hourly concentrations of each pollutant. The Air Quality Health Index and data collected from our monitoring stations are posted on this website every hour, 24 hours a day, seven days a week. </p> <p>As part of a partnership with Environment and Climate Change Canada, Air Quality Health Index values and forecasts will also posted on the Environment and Climate Change Canada <a href="https://www.canada.ca/en/environment-climate-change/services/air-quality-health-index.html" >website</a>. Each year, the ministry prepares an <a href="/press/publications.php">Air Quality Report</a> to assess the state of air quality in Ontario based on the provincial Air Quality Health Index network. </p> <a name="content" id="content"></a> <div class="row three_cols"> <div class="header"> <span class="more"><a href="/press/xml.php" title="Air Quality Health Index ATOM feeds">ATOM<img alt="RSS Feeds" src="/on_template/icon_rss.gif" /></a></span> <h2><a href="/aqhi/" style="color:#123207;" title="AQHI Observations and Forecasts"><span class="">March 19, 2025:</span> Observations and Forecasts</a></h2> </div> <div id="spotlight"> <div class="column"> <div class="content"> <div class="photo" style="background-color:#ffffff; color: #42782f"> <div class="photocap photo_top mycolour" style="background-color:#42782f; color:#ffffff;"></div> <img src='/images/clearDayForest.png' alt="AQHI Forecast Map" /> <div class="photocap photo_bottom mycolour" style="background-color:#42782f; color:#ffffff;"></div> </div> <h3 style="margin-bottom:0"><a href="/aqhi/locations.php?forecast_period=2&text_only=1" title="Table: AQHI Forecasts" >Air Quality Health Index Forecast: Low to Moderate Risk</a></h3><p style=""><strong>AQHI Forecasts:</strong> Air Quality Health Index Forecast for Tuesday night of low to moderate risk for the province of Ontario. For details, see current AQHI Forecast <a href="/aqhi/locations.php?forecast_period=2" class="blackLink" title="Map: AQHI Forecast">Map</a> or <a href="/aqhi/locations.php?forecast_period=2&text_only=1" class="blackLink" title="Table: AQHI Forecast">Table</a>.</p> </div> </div> <div class="column"> <div class="content"> <div class="photo" style="background-color:#ffffff; color: #42782f"> <div class="photocap photo_top mycolour" style="background-color:#42782f; color:#ffffff;"></div> <img src='/images/clearDayToronto.png' alt="Clear day in Toronto" /> <div class="photocap photo_bottom mycolour" style="background-color:#42782f; color:#ffffff;" ></div> </div> <h3 style="margin-bottom:0;"> <a href='/aqhi/index.php' title="Table: Current and Forecast AQHI" >Current and Forecast Air Quality Health Index (AQHI)</a> </h3> <p><strong>Hourly AQHI Reports:</strong> The AQHI is issued hourly and is a scale designed to help you understand what the quality of the air around you means to your health. It is based on the following pollutants in our air: <span id="aqhi-pollutant-links" > <a href="/science/pollutants/ozone.php" class="blackLink" >Ozone (O<sub style="">3</sub>)</a>, <a href="/science/pollutants/particulates.php" class="blackLink">Fine Particulate Matter (PM<sub>2.5</sub>)</a>, <a href="/science/pollutants/nitrogen.php" class="blackLink">Nitrogen Dioxide (NO<sub>2</sub>)</a>. </span> </p> </div> </div> <div class="column"> <div class="content"> <div class="photo" style="background-color:#ffffff; color: #42782f"> <div class="photocap photo_top mycolour" style="background-color:#42782f; color:#ffffff;"></div> <img src='/images/clearDayKidsTree.png' alt="Clear day with children" /> <div class="photocap photo_bottom mycolour" style="background-color:#42782f; color:#ffffff;"></div> </div> <h3 style="margin-bottom:0;"> <a href='/history/summary.php' title="Pollutant Summary">Local, Live and Historical Data</a></h3> <p><strong>Real-Time Pollutant Data:</strong> The Ontario Ministry of the Environment, Conservation and Parks reports real-time <span id="monitored-pollutant-links" ><a href="/science/pollutants/ozone.php" class="blackLink" >O<sub style="">3</sub></a>, <a href="/science/pollutants/particulates.php" class="blackLink">PM<sub>2.5</sub></a>, <a href="/science/pollutants/nitrogen.php" class="blackLink">NO<sub>2</sub></a>, Carbon Monoxide (<a href="/science/pollutants/carbon.php" class="blackLink">CO</a>), and Sulphur Dioxide (<a href="/science/pollutants/sulphur.php" class="blackLink">SO<sub>2</sub></a>) </span> data in geographical, graphical and tabular formats every hour. See the newest results: <a href='/history/summary.php'>Current Pollutant Concentrations</a>.</p> </div> </div> </div> </div> </div> <div id="left_column">  <div class="leftnav"> <div class="photocap nav_top mycolour" style="background-color: #2c5b0a;"></div> <div style="color:white; background-color: #2c5b0a;"> <img height="120" width="250" class="photo" alt="Clear day in Ontario" src="/images/skyflower.png" style="float:none;margin-bottom:6px;" /> <span class="text" style="color:white;font-size: 1.1em"> <img height="9" width="9" class="mobilehide" src="/images/arrowwhite_right.gif" alt="Open/Close Menu Arrow" /> <a href="/aqhi/locations.php?forecast_period=3" title="Map: AQHI Forecast" style="color:white;"> AQHI Forecast Map</a> <a href="/aqhi/locations.php?forecast_period=3&text_only=1" title="Table: AQHI Forecast" style="color:white;">(Table)</a> </span></div> <div class="photocap nav_bottom mycolour" style="background-color: #2c5b0a;" ></div> </div> <div class="leftnav"> <div class="photocap nav_top mycolour"></div> <div class="mycolour"><h2 class="header"><a style="display:block;" href="/" >Air Quality Ontario: Home Page</a></h2></div> <ul class="menu clear" id="smenu1" style="display:block;" > <li> <a href="/aqhi/index.php" >Air Quality Health Index (AQHI)</a></li> <li><a href="/alerts/signup.php">Air Quality Alert Email Notifications</a></li> <li><a href="/history/summary.php">Pollutant Concentrations</a></li> <li><a href="/press/publications.php">Air Quality Publications</a></li> <li class="menu clear"><a href="/science/" >Information about Air Quality</a></li> </ul> </div> <div class="leftnav"> <div class="photocap nav_top" style="background-color: #4a1910;"></div> <div class="mygovt"><h2 class="header"><a style="display:block;" href="javascript:void(0)" onclick="showHide('smenu5');return false;"> Explore Government<img src="/images/arrowwhite_right.gif" width="9" height="9" alt="Open/Close Government Menu Arrow" id="smenu5_arrow" title="Open the explore menu" /></a></h2></div> <ul class="menu" id="smenu5"> <li><a href="http://www.ontario.ca/en/residents/index.htm">Ontario.ca</a></li> <li><a href="https://www.ontario.ca/page/premier">Premier of Ontario</a></li> <li><a href="http://ontario.ca/MAA">Aboriginal Affairs</a></li> <li><a href="http://ontario.ca/OMAFRA">Agriculture, Food and Rural Affairs</a></li> <li><a href="http://ontario.ca/MAG">Attorney General</a></li> <li><a href="https://www.ola.org/en/members/all/victor-fedeli">Chair of Cabinet</a></li> <li><a href="http://ontario.ca/MCYS">Children and Youth Services</a></li> <li><a href="http://ontario.ca/MCI">Citizenship and Immigration</a></li> <li><a href="http://ontario.ca/mcss">Community and Social Services</a></li> <li><a href="http://ontario.ca/MCSCS">Community Safety and Correctional Services</a></li> <li><a href="http://ontario.ca/MCS">Consumer Services</a></li> <li><a href="http://ontario.ca/MEDT">Economic Development and Trade</a></li> <li><a href="http://ontario.ca/EDU">Education</a></li> <li><a href="http://ontario.ca/MEI">Energy</a></li> <li><a href="http://ontario.ca/MOE">Environment</a></li> <li><a href="http://ontario.ca/MOF">Finance</a></li> <li><a href="http://ontario.ca/OFA">Francophone Affairs</a></li> <li><a href="http://ontario.ca/MGS">Government Services</a></li> <li><a href="http://ontario.ca/MOH">Health and Long-Term Care</a></li> <li><a href="http://ontario.ca/MHP">Health Promotion and Sport</a></li> <li><a href="http://ontario.ca/MEI">Infrastructure</a></li> <li><a href="http://ontario.ca/MIA">Intergovernmental Affairs</a></li> <li><a href="http://ontario.ca/MOL">Labour</a></li> <li><a href="http://ontario.ca/MAH">Municipal Affairs and Housing</a></li> <li><a href="http://ontario.ca/MNR">Natural Resources</a></li> <li><a href="http://ontario.ca/MNDMF">Northern Development, Mines and Forestry</a></li> <li><a href="http://ontario.ca/MRI">Research and Innovation</a></li> <li><a href="http://ontario.ca/revenue">Revenue</a></li> <li><a href="http://ontario.ca/OSS">Seniors’ Secretariat</a></li> <li><a href="http://ontario.ca/tourism">Tourism and Culture</a></li> <li><a href="http://ontario.ca/TCU">Training, Colleges and Universities</a></li> <li><a href="http://ontario.ca/MTO">Transportation</a></li> <li><a href="http://ontario.ca/OWD">Women’s Directorate</a></li> </ul> </div> <div class="leftnav"> <div class="photocap nav_top mycolour"></div> <div class="mycolour"><h2 class="header"><a style="display:block;" href="javascript:void(0)" onclick="showHide('smenu6');return false;">Contacts <img src="/images/arrowwhite_right.gif" width="9" height="9" alt="Open/Close Contact Menu Arrow" title="Open the contact menu" id="smenu6_arrow" /></a></h2></div> <ul class="menu clear" id="smenu6"> <li><a href="/press/information.php">Contact Air Quality Ontario</a></li> <li><a href="/alerts/signup.php">Air Quality Email Sign-up</a></li> <li><a href="http://www.infogo.gov.on.ca/infogo/searchDirectory.do?actionType=searchtelephone&infoType=telephone&locale=en">Telephone Directory</a></li> <li><a href="https://www.ontario.ca/locations/serviceontario">ServiceOntario Locations</a></li> <li><a href="https://www.ola.org/en/members/current">MPPs</a></li> </ul> </div> </div> <div id="footer">  <script type="text/javascript" src="/on_template/moe_footer.js"></script>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-73PCSK3J3H"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-73PCSK3J3H'); </script>  </div> </div> </body> </html>