CHICAGO - The air in Chicago isn’t colored in a hazy dystopian orange like some parts of the East Coast, but wildfires raging in Canada may continue to affect air quality in the city and across Illinois for the next several days.
The effects of wildfires burning in Quebec could be felt Wednesday as far as North Carolina to the south and Ohio to the west. Conditions were especially hazardous in parts of central New York, where the airborne soot was at hazardous levels, turning the air a yellowish gray and prompting warnings to stay inside.
In Illinois, air quality was classified as moderate Wednesday, including in Chicago, according to the Illinois Environmental Protection Agency. Conditions were forecast to remain at that level until Sunday.
That classification means air quality is acceptable, but pollution in this range may pose a moderate health concern for people who are unusually sensitive to ozone or particulate pollution, the EPA said.
The air quality in some parts of southern Cook County, near Tinley Park, Dolton, South Holland and Chicago Heights, was classified as unhealthy for sensitive groups due to a high level of fine particulate matter in the atmosphere from smoke blown into the area.
The tiny particles are small enough to get past airway defenses and cause breathing and circulatory difficulties.
Those with heart or lung ailments, older adults, and children and teens were advised to shorten the amount of time they spend active outdoors and to avoid strenuous activities to reduce their risk of a health issue, the state EPA said. People in these groups should take extra precautions and watch for symptoms like coughing, difficulty breathing or fatigue.
"We’ve been in sort of a stagnant weather pattern, with winds out of the Northeast that is dragging wildfire smoke toward the Great Lakes," said National Weather Service meteorologist Brett Borchardt. "We’ve been stuck in this pattern for a few weeks now."
On Monday, poor air quality readings prompted the state to declare an Air Pollution Action Day. And the Illinois EPA issued a statewide air quality alert.
The good news, Borchardt said, is that the wind pattern is expected to begin to shift this weekend, blowing some of the smoke away from the area.
"Once we get toward the weekend, into Saturday and Sunday, it does look like the pattern does shift," Borchardt said. "We’re expecting a cold front to come through this weekend, and then the wind directions are gonna be at that point changing to more of a westerly direction after the cold front."
Residents can get air quality data for their area by visiting AirNow.gov and plugging in their ZIP code.
Experts say prolonged hot, dry weather is the primary driver of the fires raging in Canada.
"The month of May was just off the charts — record warm in much of Canada," said Eric James, a modeling expert with the Cooperative Institute for Research in Environmental Science at the University of Colorado, who is also with the National Oceanic and Atmospheric Administration.
Those unusual conditions — made worse by the effects of climate change — increased the risk of fires, he said.
The right mix of circumstances had to align for the smoke to blanket major U.S. cities: A dry, hot spring set the stage for big fires. Then weather did the rest, said Bob Henson, meteorologist with Yale Climate Change Connections.
"It’s a simple matter of trajectory," Henson said. "The smoke goes where the wind takes it."
There is an area of low air pressure around Nova Scotia, and air is circulating in a big arc to its west.
"That’s the mechanism for bringing down all the smoke," James said.
The particulate matter from the smoke in some pockets of Illinois was considered unhealthy for some, but the levels currently blanketing much of the Northeast are not healthy for anyone.
Major League Baseball postponed games in New York and Philadelphia Wednesday night because of poor air quality from the smoke.
New York Gov. Kathy Hochul warned the public to "prepare for this over the long haul." New York City Mayor Eric Adams told residents to limit outdoor activities, and parks officials closed beaches as smoke shrouded the skyline.
Performances of "Hamilton" and "Camelot" on Broadway, as well as a Shakespeare in the Park production of "Hamlet," were canceled on Wednesday night due to smoke.
The Federal Aviation Administration paused some flights bound for LaGuardia Airport and slowed planes to Newark Liberty and Philadelphia airports because the smoke was limiting visibility. It also contributed to delayed arrivals at Dulles International Airport outside Washington, D.C.
The Associated Press contributed to this report.