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.

Wednesday, May 3 - Tuesday, May 9, 2023

Ozone

Good to Moderate levels.

Particle pollution (PM_2.5)

Good to Moderate levels.

Short-Term Forecast Maps:

The daily AQI is forecast for counties that monitor each pollutant of interest. 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)

The slow-moving low which has impacted the state over the last several days will finally move off into the Atlantic on Wednesday. Mostly sunny skies are expected to the west, while eastern areas will see partly cloudy skies. An increasing temperature trend should begin with western areas pushing into the 60s while a lake breeze will keep eastern areas cool. Good AQI is forecast statewide, with a slight chance to see Low-Moderate AQI ozone in western areas downwind of MSP. On Thursday, a weak low-pressure system will move into the state from the northwest, bringing isolated AM showers and PM storms to northern Wisconsin. A southerly flow will see southern Wisconsin temperatures push into the 70s as a frontal boundary sets up across the state. Areas south of this front should remain mostly dry, but chances for Moderate AQI ozone or PM2.5 will be on the increase. By Friday, a more well-defined boundary will be draped across the southern part of the state. Shower chances will be on the increase along and north of this boundary, while areas south of it will have a better chance to remain dry. An easterly component to the flow will increase in magnitude, so although western areas will reach into the 70s once again, eastern areas will remain cooler. Moderate AQI ozone and PM2.5 are expected along and south of the boundary where pollutant concentrations will tend to accumulate.

Extended Outlook (Days 4-7)

The front should lift north by Saturday, leading to precipitation chances for northern areas while southern areas should remain mostly dry. Moderate AQI potential will also ride north with the front. Sunday through Tuesday currently look to have heavier cloud cover and better chances for precipitation, especially Monday. Moderate AQI potential will stick around in areas of decreased cloud cover and precipitation, but areas locked into heavier cloud cover or precipitation should trend towards Good AQI.

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].