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Noise monitoring program
Active Air Quality Notification
  • An air quality ADVISORY for Unhealthy PM2.5 levels is in effect from 7/12/2025 00:00 to 7/14/2025 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,Pierce,Pepin,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.

Friday, July 11 - Thursday, July 17, 2025

Ozone

Good to USG AQI levels.

Particle pollution (PM2.5)

Good to Very 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)

A mix of clear skies and light showers are observed across Wisconsin this morning. Surface high pressure in place over northern Wisconsin is associated with relatively calm conditions and light southeasterly flow. A weak low pressure system developing along a stationary boundary over the Nebraska/Iowa border is producing scattered showers up into western portions of Wisconsin. Throughout the day today, southerly flow over Wisconsin will continue as the low pressure to the southwest traverses east, bringing additional precipitation to the southern half of Wisconsin. Good AQI for both PM2.5 and ozone is expected today for most of the state. A couple sites may tick up into the Low-Moderate AQI range for PM2.5. As today’s system progresses east, another low pressure system currently centered over the Minnesota/Ontario border will also track east, with an associated cold front moving through northern Minnesota into the region. Behind this cold front in southern Manitoba and eastern North Dakota, a thick plume of smoke originating from multiple active fire complexes spanning central Manitoba and Saskatchewan is currently producing significant PM2.5 impacts at the surface. This front is expected to enter Wisconsin from the northwest overnight tonight into tomorrow morning. Increasing PM2.5 concentrations associated with incoming smoke are expected to begin as early as midnight Friday night for far northwestern Wisconsin, with the heaviest smoke currently anticipated throughout the day on Saturday. Unhealthy for Sensitive Groups (USG) to Unhealthy AQI for PM2.5 is expected, with the heaviest smoke impacts more likely for the northern half of the state. Brief periods of Very Unhealthy to Hazardous NowCast AQI will be possible. Surface high pressure will move into the region immediately behind the cold front Saturday night into Sunday, producing westerly flow and mostly cloudless skies. Impacts from smoke are expected to persist statewide as large-scale subsidence may assist with mixing smoke aloft towards the surface while westerly flow transports any additional smoke over Minnesota into Wisconsin. USG to Unhealthy AQI for PM2.5 is forecast to continue, though high Moderate AQI may be observed for some locations if additional smoke aloft does not mix down to the surface. Ozone may also tick into the Moderate to USG AQI range for locations that continue to see impacts from smoke if enough sunlight can make it through to the surface, as high temperatures will reach the upper 70s to low 80s.

Extended Outlook (Days 4-7)

There is significant uncertainty in the extended forecast, pending on what is observed this weekend. In addition to any lingering smoke from Sunday, long-range guidance suggests another cold front associated with an upper level shortwave over Ontario pushing south into northern Minnesota and Wisconsin Monday morning. If this verifies, there is potential for another band of smoke to move into the region behind this front. For now, Moderate to Unhealthy AQI for PM2.5 is forecast for Monday, with higher chances for USG to Unhealthy AQI across locations farther north. Ozone enhancement is also forecast to continue where smoke is present – Moderate AQI is forecast for now, with potential for USG AQI. Flow will likely shift to southerly by Tuesday morning as the next low pressure system builds over the northern Great Plains and tracks east into the region. Assuming cleaner air to the south, this southerly flow and associated precipitation may act to clear out any smoke still present over Wisconsin. However, any smoke still trapped over Lake Michigan could enhance ozone production within the marine boundary layer as high temperatures in the upper 80s are expected. For now, Moderate AQI for ozone and PM2.5 is forecast for Tuesday, with USG AQI possible along the lakeshore. Behind Tuesday’s low pressure system, northerly flow and subsequent high pressure influence is expected Wednesday and Thursday. Pending the status of ongoing Canadian fires and associated smoke, additional PM2.5 and ozone impacts cannot be ruled out.

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].