Current air quality outlook
Department meteorologists use monitoring data and weather forecast models to predict Wisconsin's future air quality using the Air Quality Index (AQI) [exit DNR]. If warranted, an Air Quality Notice is issued. Below is the latest air quality forecast for Wisconsin.
Wednesday, July 28 - Tuesday, August 03, 2021
Good to USG levels.
Particle pollution (PM2.5)
Good to USG levels.
Wednesday - The focus for today’s weather forecast will be the potentially significant severe weather event which will move from NW to SE this afternoon/evening into early Thursday morning. Please remain weather aware and have a plan in place in case severe weather approaches your area. Hot and muggy conditions will persist ahead of the system with slightly cooler temperatures near the lake thanks to onshore flow. PM2.5 concentrations are expected to remain elevated in the Moderate AQI range thanks to lingering wildfire smoke. Ozone concentrations will be elevated in southeastern and lakeshore areas once again today. Some upper-level cloud cover from ongoing storms in MN could help to limit ozone production, but we are going to forecast USG AQI for the lakeshore from Sheboygan Co. south to Kenosha Co. There is a potential for these USG AQI ozone concentrations to move inland of southeastern lakeshore counties, but for now we’ll forecast Moderate AQI ozone for these areas.
Weather map for Wednesday, July 28, 2021. Graphic is courtesy of the NOAA/NWS Weather Prediction Center.
Thursday - Behind the significant wind and rain event northerly flow and Good AQI ozone is anticipated to make a return alongside cooler and less humid air. However, smoke from Canadian wildfires will once again be transported south, likely impacting the surface mostly in the western half of WI. Currently, we are going to keep a Moderate AQI PM2.5 forecast, but it will be possible for this to be upgraded to USG AQI.
Weather map for Thursday, July 29, 2021. Graphic is courtesy of the NOAA/NWS Weather Prediction Center.
Friday - As high pressure moves over the area another mostly pleasant day is anticipated with high temperatures in the 70s to right around 80 and low humidity. Good AQI ozone is anticipated to continue while PM2.5 concentrations look to remain elevated due to wildfire smoke. Similar to Thursday, Moderate AQI PM2.5 will be forecast for now, but there will be a chance for this to be upgraded, especially in western or northern areas.
A brief return of warmer temperatures and precipitation chances on Saturday will lead to a potential for Moderate AQI ozone. A northerly flow regime will then lead to a cooler weather pattern and Good AQI ozone to begin next week. PM2.5 AQI will be much more in question as this northerly flow will have the potential to bring wildfire smoke into the area. Moderate AQI PM2.5 is forecast through the extended period for now, but this will need to be revisited.
Note: All weather maps are courtesy of the NOAA/NWS Weather Prediction Center [exit DNR].
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].