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.

Updated Thursday, October 30 - 9:20 AM

Thursday, October 30 - Wednesday, November 5, 2025

Ozone

Good (Green) AQI levels.

Particle pollution (PM_2.5)

Good (Green) to Moderate (Yellow) 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)

Fog has developed in low lying areas and river valleys Thursday morning, leading to slight PM2.5 enhancements, mostly across the Driftless Area. Although Good (Green) AQI PM2.5 is forecast statewide on Thursday, there will be a chance for this area to end up in the Low-Moderate (Low-Yellow) PM2.5 AQI range. North to northwest winds should then be slightly more active on Friday and Saturday as an upper-level disturbance moves through. During this period, some areas of central and southern Wisconsin may see their first snowflakes of the season. Good (Green) AQI is forecast to continue Friday and Saturday.

Extended Outlook (Days 4-7)

Good AQI is forecast through the extended period. Breezy SW winds are expected to develop from west-to-east on Sunday ahead of a low pressure system tracking east through the Canadian Provinces. The associated cold front and accompanying precipitation chances will then roll through the state Sunday evening into Monday morning. Behind this front, gusty westerly winds are anticipated for Monday. The active pattern looks to continue mid-week as another system moves from the Plains into the Great Lakes region Tuesday into Wednesday.

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].