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 frequently, and when warranted, an Air Quality Advisory is issued. Below is the latest air quality forecast for Wisconsin.

Updated Friday, September 25 - 4:45 p.m.

Saturday's Forecast (September 26)

High pressure will lift northeast as an upper-level trough moves in from the west. Southeasterly flow and seasonable temperatures are expected, with showers possible through the p.m. hours across western areas. Although Moderate (Yellow) AQI PM2.5 will be possible, Good (Green) AQI is forecast.

Sunday's Forecast (September 27)

A.m. showers will remain possible mostly across the western half of the state. Drier conditions should then prevail through the p.m. hours as high pressure builds back in. Once again, Moderate (Yellow) AQI PM2.5 will be possible, but mostly Good (Green) AQI is expected.

Monday’s Forecast Trend (September 28)

Air quality is expected to remain satisfactory.

Forecast Maps:

The black dots represent the approximate location of Wisconsin's air quality monitors. The black borders approximate Wisconsin's Reporting Area boundaries on EPA's AirNow website [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].