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 Sunday, September 6 - 8:40 p.m.

Monday's Forecast (September 7)

High pressure will slowly drift east over the Great Lakes region while low pressure will move from the Intermountain West into Manitoba. Mostly dry conditions and Good (Green) AQI are forecast.

Tuesday's Forecast (September 8)

The Manitoba low will move northeast towards Hudson Bay and associated precipitation chances will sweep northwest-to-southeast across the state. Moderate (Yellow) AQI ozone is expected within the lake breeze along Lake Michigan, with a nonzero chance for Unhealthy for Sensitive Groups (Orange) AQI to develop. Otherwise, Good (Green) AQI is forecast.

Wednesday’s Forecast Trend (September 9)

Air quality is expected to improve.

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].