Department meteorologists use monitoring data and weather forecast models to predict Wisconsin's future ozone (O3) and fine particulate matter (PM2.5) 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 Monday, January 5 - 9:45 AM

Monday, January 5 - Sunday, January 11, 2026

Ozone

Good (Green) AQI levels.

Particle pollution (PM2.5)

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)

Seasonably warm temperatures and Moderate (Yellow) AQI PM2.5 concentrations are in place across the state Monday morning. A weak system will move through late tonight into Tuesday morning, bringing mostly rain to the southern third of the state, while freezing rain will be possible further north. Despite the passage of this system, Moderate (Yellow) AQI PM2.5 is forecast to continue. Clearing skies look to move in from the west on Wednesday with southerly flow maintaining seasonably warm temperatures. Although some improvements in PM2.5 concentrations are expected, statewide Moderate (Yellow) AQI remains forecast.

Extended Outlook (Days 4-7)

Although plenty of uncertainty remains in the extended forecast, there currently appears to be a couple of chances for precipitation as a boundary sets up near the Great Lakes. The first is in the late Thursday to early Friday timeframe, with mostly rain expected. The second chance arrives late Friday through Saturday with accumulating snow possible. Moderate AQI PM2.5 potential will stick around Thursday, but we should then trend more towards Good AQI on Friday and over the weekend.

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].