Chicago and much of the Upper Midwest were blanketed in a smoky haze from the Canadian wildfires Tuesday, leaving many residents of the nation’s third-largest city startled by the sudden decline in air quality and wearing masks when venturing outside .
Chicagoans were largely spared the severe effects of wildfires earlier this month, as dangerous smoke engulfed the Northeast and pockets of the Midwest for days on end. But they were given no respite Tuesday as authorities classified the air as unhealthy in the city and other parts of Illinois, Wisconsin, Indiana, Michigan and Minnesota.
In Chicago, the air quality index reached 209 at noon, the worst reading of any major city in the world for the day, according to IQAir, a Swiss air quality technology company. In Green Bay, Wisconsin, the index was 175; in Grand Rapids, Michigan, it rose to 255. Any reading above 100 on the index is a warning to people with respiratory problems to take precautions.
Mayor Brandon Johnson of Chicago has warned residents, especially children, the elderly and people with heart or lung disease, to stay indoors if possible, or wear masks if they must be outside, to avoid the worst effects of the smoky air.
“This summer, cities across North America have seen unhealthy levels of air quality due to smoke from wildfires, affecting more than 20 million New York City people; Washington DC; Montreal; and here in Chicago today, » Johnson said in a statement. « As we work to address immediate health concerns in our communities, this troubling incident demonstrates and underscores the detrimental impact the climate crisis is having on our residents, as well as people from all over the world ».
Similar levels of smoke, and perhaps even denser concentrations, were expected in other cities in the region on Tuesday, including Milwaukee.
« Today would normally be considered a good day to go out », meteorologists with the National Weather Service office in Milwaukee he wrote. « But the smoke is reducing visibility to just a mile to three miles today. »
Conditions should improve overnight in Chicago and Milwaukee, but haze should persist on Wednesday.
New York officials warned that hazy skies could return to their state on Wednesday. Governor Kathy Hochul said air quality could be poor in the western and central parts of the state and other areas could be affected as well.
« Due to the winds blowing in tonight and the wildfires in Canada going on, New York City could experience worse air quality tomorrow, » Mayor Eric Adams said on Twitter on Tuesday, reminding New Yorkers to wear a mask if they leave the house on Wednesday.
Many people in Chicago seemed taken aback by the sudden influx of smoke, since the city is rarely affected by air pollution from wildfires. « Has anyone noticed a strange acrid smell in the neighborhood? » asked a North Side resident on a Nextdoor forum Tuesday morning.
Summer camps have rushed to make new plans for the kids, keeping them indoors and away from polluted air. Along the shore of Lake Michigan, in areas usually packed with joggers, bikers and sunbathers during mild Chicago summers, the lakefront seemed largely deserted on Tuesday.
The Michigan State Veterinary Office has issued a warning to people who own pets, reminding owners that strenuous activity should be avoided and that birds too can be affected by the unhealthy air.
The Minnesota Pollution Control Agency issued its 23rd air quality advisory of the year on Tuesday — a record — as a layer of smoke hung over much of the state.
David Brown, an air quality meteorologist at the agency, said Minnesota typically issues no more than two or three air quality alerts a year. The previous record was 21 alerts for all of 2021, he said.
Mr. Brown said wildfire season in Canada usually doesn’t even start until early July, so Americans in northern states could face the threat of poor air quality for weeks to come.
« There are a lot of fires that are getting very big, with the hottest days yet to come, » he said. « These fires will likely continue to grow. »
The last air quality advisory for Minnesota, issued Tuesday morning, was due Thursday. It covers much of the southern and eastern areas of the state.
Judson Jones AND Ernest London contributed report.