Chicago Air Quality Alert extended as wildfire smoke from Canada, Minnesota creates haze, poor conditions

An Air Quality Alert for the Chicago area is only being made worse by the arrival of drifting smoke from wildfires in Canada and Minnesota.

The National Weather Service has placed Cook, Lake, McHenry, Kane, DuPage, Kendall, Kane and Grundy counties in Illinois and Lake, Porter, Newton and Jasper counties under an Air Quality Alert through Thursday night as high ozone levels and wildfire smoke combine. 

But the poor air quality will also be exacerbated by the arrival of smoke from Canadian and Minnesotan wildfires, especially in the northern part of our area.

By Thursday afternoon, most of Chicago's northern suburbs as well as the northern parts of the city and along the lakefront is expected to experience unhealthy to very unhealthy air quality because of the smoke. That is expected to last until at least Friday morning. On the Air Quality Index, unhealthy is between 151 and 200, and very unhealthy is 201-300. 

In just the last few years, Chicago has recorded unhealthy air quality twice, on June 27, 2023 with an AQI of 175 and on July 31, 2025 with an AQI of 174. On both those days, while the AQI was highest, Chicago had the worst air quality in the world. 

Officials in Michigan and Wisconsin warned residents Tuesday about air quality issues that could last for days. High levels of fine particulate matter in the air from wildfire smoke may be unhealthy for sensitive groups, such as children and people with heart or lung conditions.

By Wednesday afternoon, intense smoke will spread into the East Coast and Midwest, including parts of the New England coast, northern Pennsylvania, Detroit and Milwaukee, said Tyler Hasenstein, meteorologist with the National Weather Service in Chanhassen, Minnesota.

In the Chicago aera, Wednesday's primary concern remains ozone levels, with greater risks from wildfire smoke pollution on Thursday. Still, Chicago's skyline was already visible hazy Wednesday morning.

"These are particles in the smoke stream that are so small that they can get to the deepest portion of your lungs and get into your bloodstream," said Brian Urbaszewski, director of environmental health programs with the Respiratory Health Association of Chicago.

"I think of the perfect storm coming for those especially who are vulnerable and have respiratory issues," said Dr. Juanita Mora, spokesperson for the American Lung Association.

The combination with high temperatures and humidity could mean people in sensitive groups – including senior citizens, children, and anyone with pulmonary or respiratory illnesses like asthma – should limit their time outdoors if at all possible.

In Crown Point, Indiana, 135 youth softball teams have gathered for the National Softball Association's Northern World Series, despite the heat and air quality.

"We came prepared," said John Lienert, coach of the Iron City Dynamite. "We've brought a couple tents for the girls to sit in the shade."

The heat and air quality can make for a brutal double-header with overlapping illness symptoms like dizziness and fatigue.

Organizers said they're keeping an eye on all weather conditions, but this is a team effort, so everyone is pitching in to keep each other safe.

"Everything we do is based around trying to take care of the ladies," said Bill Horton, president and CEO of the National Softball Association.

"We try and make sure that we cover all of our bases. so the good part about it is we've got a lot of good families that are a part of our organization and a part of our team. And they pitch in so all the stuff that you see here it wasn't just one person," said Lienert.

Organizers said it's unlikely they'll have to shift any games around for the heat or the air; when it comes to weather there's one thing that tops everything: rain.

Experts say these alerts and conditions are a good reminder to treat air quality like the weather.  Before you make plans to go outside, check the Air Quality Index, and if you notice a new cough, shortness of breath or feel winded more easily, it may be time to head inside.