Noise monitoring program

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.

Friday, September 29 - Thursday, October 5, 2023


Good to Moderate levels.

Particle pollution (PM2.5)

Good levels.

Short-Term Forecast Maps:

Forecast AQI maps for the short-term forecast period.

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 cut-off low that has brought numerous days of overcast skies and multiple rounds of precipitation this week will continue moving off to the east today. High pressure will take over as the dominate meteorological driver at the surface, pivoting winds to southeasterly and kicking off a brief warming trend as we head into the weekend. High temperatures today are expected to reach the upper 60s to low 70s, with continued precipitation chances for western WI. Ozone and PM2.5 are expected to remain in the Good AQI range today. Temperatures will be on the rise tomorrow, with highs anticipated to reach the upper 70s to low 80s. Southerly winds and clear skies over southern Wisconsin will increase potential for ozone production. Moderate AQI for ozone is forecast for the lakeshore, with Good AQI forecast elsewhere. PM2.5 is expected to remain in the Good AQI range. On Sunday, southerly winds will remain in place, allowing high temperatures to reach the low to mid 80s. Ozone is expected to again reach Moderate AQI along the lakeshore, with inland counties more likely to remain in Good to Low-Moderate AQI. PM2.5 is forecast to remain in the Good AQI range.

Extended Outlook (Days 4-7)

By Monday, a large upper level disturbance will be moving through the western U.S. High pressure will remain the dominate driver over Wisconsin, with southerly winds and high temperatures in the 80s. Good to Moderate AQI for ozone is expected to persist, with PM2.5 likely to remain in the Good AQI range. As the upper level wave approaches the Midwest, an associated low pressure system will develop at the surface. Current long-range guidance suggests the cold front from this system will impact Wisconsin Wednesday afternoon into Wednesday evening. Elevated ozone may be observed ahead of the cold front, so timing of frontal passage will likely impact peak pollutant concentrations. For now, Moderate AQI for ozone is forecast for eastern Wisconsin, with Good AQI more likely for counties farther west. On Thursday, northerly winds and a clean airmass will bring a significant temperature drop and Good AQI statewide for both ozone and PM2.5.


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].