Wisconsin air quality among nation’s worst as Canadian wildfire smoke spreads

Unhealthy air is blanketing Wisconsin as smoke spreads from wildfires burning in Canada. 

As of Thursday, the Upper Midwest was contending with the worst air quality in the country. And, for much of the day, Milwaukee had the worst air quality of any major U.S. city, according to a ranking from IQ Air.

Statewide, an air quality advisory remains in effect until at least noon on Friday. But Craig Czarnecki, a spokesperson with the Wisconsin Department of Natural Resources, warns it’s likely to be extended. He said recent rainstorms helped blow Canadian wildfire smoke into Wisconsin.

“This is a very large plume of smoke that kind of the whole Upper Midwest is dealing with right now,” Czarnecki said. “There’s chances of this kind of lingering through the weekend.”

‘This is pretty sucktastic’

Natasha Prather was among the Wisconsinites coughing through the bad air Thursday. She’s a barista who rode her bike to work at the Anodyne Coffee Shop in Milwaukee’s Bayview neighborhood.

“Well, I leave my apartment windows open, so I woke up with a sore throat, and my lungs hurt and everything,” Prather said.

Thursday’s air quality conditions in Wisconsin are on track to be the state’s worst so far in 2025, said State Climatologist Steve Vavrus. He said the state hasn’t seen air this bad since two summers ago, when smoke from Canadian wildfires were also to blame.

“It’s hard to find many days in the past 25 years that have had worse air quality in Wisconsin than right now,” Vavrus said Wednesday afternoon.

Wildfires tend to rage in Canada during hot and dry summers. And, when the wind patterns are just right, that smoke can blow down into Wisconsin.

The bad news: Because of climate change, those conditions are likely to occur more and more often, Vavrus said.

“Climate change is favoring more frequent and intense wildfires, especially in more northern locations like Canada,” Vavrus said. “Ultimately that increases the odds that downstream somewhere will experience the wildfire smoke.

For Wisconsinites like Prather, that could mean more days spent dealing with scratchy throats and hazy skies.

“This is pretty sucktastic” Prather said of Thursday’s dirty air. “Climate change sucks.”

How Wisconsinites can limit negative health effects of wildlife smoke

Until the air clears up, Wisconsinites are advised to limit their time outside, and to avoid heavy outdoor exercise. People can reduce their exposure by running an air filter and by staying inside with the windows and doors closed.

If you are outdoors for an extended time period, the DNR recommends wearing an N95 mask. That’s especially true for those at higher risk, including children, the elderly and people with heart or lung disease.

WPR’s Evan Casey contributed reporting.