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.

Tuesday, January 21 - Monday, January 27, 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)

Good AQI is forecast through the short-term period. Frigid temperatures and wind chills will accompany mostly sunny skies on Tuesday, with winds turning southwesterly and cloud cover increasing through the PM hours as a clipper system approaches the area. For Wednesday, temperatures will be relatively warmer but remain seasonably cool alongside mostly cloudy skies and light snow showers. Given the southwesterly flow ahead of the clipper system’s cold front, Low-Moderate AQI PM2.5 will be possible across southeast Wisconsin. As winds turn back northwesterly on Thursday, temperatures will take a dip once again while cloud cover decreases throughout the day.

Extended Outlook (Days 4-7)

Southerly flow and relatively warmer temperatures will return on Friday as high-pressure moves over the southeast and low-pressure moves into Hudson Bay. An associated cold front will take its time to move across the state during the Friday to Saturday timeframe, allowing for Moderate AQI PM2.5 potential on Friday before increasing winds on Saturday diminish these chances. Decreasing clouds, southwesterly flow, and moderating temperatures are then forecast for Sunday and Monday, with high temperatures above the freezing mark for some areas not out of the question by Monday. Good AQI is forecast for Sunday, before Moderate AQI PM2.5 potential returns Monday as winds turn southwesterly.

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].