Department meteorologists use monitoring data and weather forecast models to predict Wisconsin's future ozone (O₃) and fine particulate matter (PM_2.5) 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, March 20 - Wednesday, March 26, 2025

Ozone

Good AQI levels.

Particle pollution (PM_2.5)

Good to Moderate AQI levels.

Short-Term Forecast Maps:

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)

Snow showers will be exiting to the east Thursday morning before northwesterly winds weaken and become southwesterly throughout the day. Good AQI is forecast under mostly sunny skies. Low-pressure will then be moving through Ontario on Friday, with an associated cold front pushing through the state. PM2.5 concentration increases are expected ahead of the front, leading to Low-Moderate AQI PM2.5 potential. However, these increases should be short lived and Good AQI is forecast on the day. Behind the front on Saturday, northwesterly winds will bring in another cool air mass accompanied by Good AQI.

Extended Outlook (Days 4-7)

Low-pressure is forecast to impact the state with a wintery mix late Saturday night through Sunday, with snow accumulations possible across northern Wisconsin. Mostly rain with storm potential is expected further south. The active pattern is expected to continue with a brief area of high-pressure moving in on Monday being quickly replaced by a return of precipitation chances Tuesday and Wednesday. Mostly Good AQI with only slight chances for Moderate AQI are forecast through the extended period.

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].