Wildfire smoke sends air quality plummeting in Chicago, Minneapolis
Wildfire smoke drifting across the central U.S. has caused air quality to plunge to hazardous levels in several states, including in Chicago where thousands are gathering for the annual Lollapalooza music festival.
With air quality becoming a concerning for the central U.S. due to wildfires in Canada, you can protect your health by monitoring pollutants in your area when you download the free AccuWeather app.
Wildfire smoke has caused air quality to plunge to hazardous levels across the central United States, affecting millions of people in major cities. Air quality alerts were in effect for all of Minnesota, Wisconsin, Michigan, Iowa and Illinois on Friday morning due to the smoke-filled air. "Unhealthy" air quality expanded farther south, reaching St. Louis and Kansas City.
Chicago had the worst air quality in the world on Thursday, with conditions remaining "unhealthy" on Friday. The hazardous air quality arrived just as Lollapalooza got underway in the city with thousands of festivalgoers spending hours outside.
A map of the air quality across the Great Lakes and surrounding areas on Aug. 1, 2025. Red indicates "unhealthy" air quality, and purple indicates "very unhealthy" to "dangerous" air quality. (AccuWeather/Plume Labs)
People in these areas may notice irritation in their throat or eyes and breathing difficulties, especially during any physical activity such as working or exercise. Sensitive groups may immediately feel the health effects when stepping outside.
Hazy views of Chicago on Friday morning when "unhealthy" air quality was reported in and around the city. (Photos/EarthCam)
Haze hung over the region and was visible on satellite and from the ground, but the smoke was not as thick or brown-tinted as it was during previous air quality outbreaks in recent history.
Health officials advise minimizing time outdoors, especially for children, older adults and people with heart or lung conditions. Those with outdoor plans are urged to reschedule, limit exertion or move activities indoors until air quality improves.
Some smoke will also make its way into the eastern and southern parts of the U.S. However, in these areas, the smoke will tend to be higher up in the atmosphere and not so much near the ground. The effect will be to make the sky appear hazy, such as during a humid day, even though the air may be dry and cool.
Canadian wildfire smoke is expected to linger around the Great Lakes and surrounding areas for days ahead as August begins.
More smoke likely as wildfires flare in US, Canada
The threat of wildfires will escalate in the coming weeks as vegetation continues to dry out across parts of the western United States.
“Wildfire season is reaching near peak in Canada but is just getting started in the western U.S.," AccuWeather Lead Long-Range Expert Paul Pastelok said. A staggering 15 million acres of land have already been scorched across Canada in 2025, with the country on pace to have its second-worst year for wildfires on record.
"We will likely see more smoky and milky skies in the coming weeks," Pastelok added.
With wildfire smoke continuing to drift across the region, air quality levels may remain elevated for the next several days. AccuWeather’s Air Quality Index offers hyperlocal, real-time updates to help you make informed decisions.
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