Chicago Mayor Brandon Johnson said the city is «carefully monitoring and taking precautions.»

“We advise children, adolescents, older adults, people with heart or lung disease, and pregnant people to avoid strenuous activities and limit their time outdoors,” Johnson said in a statement released Tuesday.

The Illinois Environmental Protection Agency issued an Air Quality Alert in effect until midnight Wednesday and encouraged Chicagoans to limit their time outdoors.

Detroit had the second worst air quality in the world on Tuesday.

The National Weather Service has issued alerts for poor air quality for northeastern Illinois, northwestern Indiana and all of southeast michigan for Tuesday and Wednesday.

The New York City skyline as smoke from the Canadian wildfires, on June 7.Lev Radin/Pacific Press/LightRocket via Getty Images file

Poor air quality is also expected in New York City on Wednesday due to «incoming winds,» according to Mayor Eric Adams.

“Poor air quality is particularly dangerous for sensitive health groups, such as people with respiratory or cardiovascular conditions,” Adams tweeted. «Bring a KN95 or N95 mask tomorrow, or plan to avoid outdoor events just in case.»

Earlier this month, emissions from approximately 400 wildfires in Canada cast an orange haze over major metropolitan areas, including New York City, Boston, Philadelphia and Washington, DC.

Canada’s wildfire season this year is the worst on record with around 29,000 square miles burning across eastern and western Canada, which is greater than the combined area burned in 2016, 2019, 2020 and 2022, Reuters reported.