Wildfire smoke in Wisconsin: Air quality hits dangerous levels

Published July 16, 2026 8:26 AM CDT

A thick blanket of wildfire smoke continues to hang over southeast Wisconsin Thursday, creating unhealthy air quality and significantly reducing visibility across the region. 

Smoke from large wildfires burning in northern Minnesota and northwestern Ontario has settled across southern Wisconsin, prompting the Wisconsin Department of Natural Resources (DNR) to continue its Air Quality Advisory.

Air Quality Hazardous Wisconsin

Why is the smoke so thick?

What we know:

A persistent northerly and northeasterly wind has transported dense smoke southward from Canada and northern Minnesota into Wisconsin. Visibility has dropped to less than 2 miles across much of southern Wisconsin, with some locations briefly seeing visibility as low as half a mile.

The thickest smoke is expected to linger through much of Thursday before southwest winds develop Friday, which should begin clearing the lower levels of the atmosphere.

Northerly wind delivers smoke

Air Quality Index in the hazardous range

Why you should care:

The Wisconsin DNR says air quality across southern Wisconsin is expected to range from Very Unhealthy (Purple) to Hazardous (Maroon) category.

Communities near Lake Michigan may experience enhanced smoke concentrations as winds interact with the shoreline.

The advisory currently runs through Thursday at noon, but state officials say it will likely be extended for at least parts of Wisconsin depending on how quickly the smoke clears.

Everyone can be affected by wildfire smoke, but some people face a much greater risk.

Those most vulnerable include:

  • Children and older adults
  • Pregnant people
  • Anyone with asthma or COPD
  • People with heart disease

If you notice coughing, wheezing, shortness of breath, chest pain or unusual fatigue, move indoors and contact your health care provider if symptoms become severe.

Hazardous Air Quality

How to protect yourself

What you can do:

If you live in southeast Wisconsin, the best strategy today is to reduce your exposure to the smoke.

  • Limit strenuous outdoor activities.
  • Keep windows and doors closed.
  • Run your air conditioner on recirculate if possible.
  • Use an air purifier if you have one.
  • If you must be outside for an extended period, consider wearing a properly fitted N95 mask.
  • Monitor local air quality before spending time outdoors.

When will it improve?

What's next:

South-eastern Wisconsin can expect thins to improve Friday as a southwest southwest winds develop and begin pushing the smoke out of southern Wisconsin. Air quality will likely return to near normal levels by late afternoon and stay clear overnight into Saturday. 

The Source: The information in this post was provided by the FOX 6 Weather Experts; NWS Sullivan; and the Wisconsin DNR. 

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