As of 9 p.m., Chicago retained the distinction of having the world's worst air quality, with an air quality index of 175. Detroit came in second with 171, according to IQAir.

Air quality in the Chicago area has remained poor for three days in a row, the NBC 5 Storm Team reported Wednesday morning.

Why is it smoky in Chicago today? Wildfires are to blame for the city's air quality - among the worst in the world Tuesday. Check our map for updates.

Chicago faces poor air quality and sweltering heat today and tomorrow, followed by scattered storms heading into the weekend.

Chicago remains in the "unhealthy" red zone. Chicagoans are advised to stay indoors, wear masks outside and utilize air purifiers to avoid the impacts of the air quality.

Users across Chicago were met Wednesday with warnings from their smartphones about the city’s air quality that led to much confusion, but was the air quality actually that bad? Across social ...

Dangerous heat and humidity will move into the Chicago area forecast this week, the NBC 5 Storm Team said, with an extreme heat watch set to take effect mid-week and “feels like” temperatures as high ...

As of Thursday morning, Chicago, Detroit and Washington, D.C. were ranked as the three cities with the worst air quality in the world, according to IQ Air's Air Quality Index.

Chicago experiences poor air quality from western U.S. wildfires every year — a result of climate change — though that usually happens much later in the summer.