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Noise monitoring program
Active Air Quality Notification
  • An air quality ADVISORY for Unhealthy PM2.5 levels is in effect from 7/31/2025 12:00 to 8/1/2025 12:00 for these counties: Adams,Ashland,Barron,Bayfield,Brown,Buffalo,Burnett,Calumet,Chippewa,Clark,Columbia,Crawford,Dane,Dodge,Door,Douglas,Dunn,Eau Claire,Florence,Fond du Lac,Forest,Grant,Green,Green Lake,Iowa,Iron,Jackson,Jefferson,Juneau,Kenosha,Kewaunee,La Crosse,Lafayette,Langlade,Lincoln,Manitowoc,Marathon,Marinette,Marquette,Menominee,Milwaukee,Monroe,Oconto,Oneida,Outagamie,Ozaukee,Pepin,Pierce,Polk,Portage,Price,Racine,Richland,Rock,Rusk,Sauk,Sawyer,Shawano,Sheboygan,St. Croix,Taylor,Trempealeau,Vernon,Vilas,Walworth,Washburn,Washington,Waukesha,Waupaca,Waushara,Winnebago,Wood .

Department meteorologists use monitoring data and weather forecast models to predict Wisconsin's future ozone (O3) and fine particulate matter (PM2.5) air quality using the Air Quality Index (AQI) [exit DNR]. This forecast is updated two-to-three times weekly throughout the year, and when warranted, an Air Quality Advisory is issued. Below is the latest air quality forecast for Wisconsin.

Thursday, July 31 - Wednesday, August 6, 2025

Ozone

Good to USG+ AQI levels.

Particle pollution (PM2.5)

Moderate to Unhealthy AQI levels.

Short-Term Forecast Maps:

Forecast AQI maps for the short-term forecast period.

The black dots represent the approximate location of Wisconsin's air quality monitors. Read the forecast summaries below for further geographic information.

Short-Term Forecast (Days 1-3)

Updated Thursday, July 31 - 11 AM
A statewide Air Quality Advisory for PM2.5 remains in effect today as Canadian wildfire smoke continues to impact surface air quality over much of the Midwest. Observations this morning show hourly PM2.5 concentrations ranging from 70 to 130 μg/m3, resulting in Unhealthy (Red) to Very Unhealthy (Purple) NowCast AQI across Wisconsin. Surface high pressure centered over northern Minnesota this morning will gradually move southeast towards northern Wisconsin throughout the day today. As this system travels, northeasterly flow over Wisconsin will transport smoke currently over northeastern Wisconsin and Michigan’s Upper Peninsula towards central and southern Wisconsin before wind speeds decrease tonight and conditions become more stagnant. Unhealthy (Red) AQI with periods of Very Unhealthy (Purple) NowCast AQI is forecast for today. High pressure will continue to be the meteorological driver Friday and Saturday, resulting in gentle winds and relatively stagnant conditions. Some clearing may occur as a pocket of cleaner air currently over southeastern Ontario moves into the region as air slowly circulates clockwise around the high pressure center. However, the high pressure airmass will still contain plentiful smoke and any clearing may be short lived as existing smoke continues to recirculate over the region. Unhealthy for Sensitive Groups (USG; Orange) to Unhealthy (Red) AQI is forecast for Friday and Saturday. Conditions will be reevaluated on a day-to-day basis through the weekend, including updates to the forecast and any associated Air Quality Advisories.

Extended Outlook (Days 4-7)

By Sunday, models suggest the surface high pressure will have traveled far enough east to induce southerly flow over Wisconsin. Current long-range guidance holds this southerly flow over Wisconsin through next week Wednesday, suggesting the lack of a major frontal feature or airmass replacement that would effectively clear out lingering smoke. However, this southerly flow may still help with dispersion and move any remaining smoke back northward out of the region. Depending on how far south the smoke plume extends prior to Sunday, Wisconsin could see additional impacts from recirculation early next week. Ozone will also be closely monitored as winds become southerly and smoke begins to clear, as remnant smoke may enhance ozone production.

Air Quality Index (AQI) ranges

For more information about AQI ranges and colors, see the U.S. EPA's Air Quality Index (AQI) Basics [exit DNR].