CHICAGO — The city is once again enduring dangerous air quality as smoke from Canadian wildfires returned to the area Saturday night.
Chicago recorded an Air Quality Index number of 128 as of Sunday evening, which is considered unhealthy for sensitive groups including children, the elderly and those with underlying health conditions, according to the Environmental Protection Agency. The index ranks air quality on a scale of 0-500, with higher numbers indicating more dangerous conditions.
Chicago had the second-worst air quality of any major city in the world for a period early Sunday before dropping to the fourth worst air quality worldwide by late Sunday, according to IQAir.
An air quality alert is in effect for the area through midnight Sunday, though the unhealthy air conditions are likely to remain in the area through Monday, according to the National Weather Service’s Chicago outpost.
Possible severe storms could sweep into the area Monday night, displacing the wildfire smoke, the weather service reported. There is some uncertainty as to whether those storms will materialize as they move east over the Mississippi River, however.
The return of dangerous air conditions comes after Chicago only saw a slight reprieve from such hazards late Friday and Saturday following a period of historically bad air quality in the city.
Pedestrians, some donning face masks, walk along Michigan Avenue in the Loop as a smoky haze lingers in the skies above Chicago on July 16, 2026 as smoke from Canadian wildfires make for “unhealthy” air quality. Credit: Colin Boyle/Block Club Chicago
Chicago’s air quality saw an air quality index reading of 638 on a scale of 500, according to the Environmental Protection Agency. The number broke the record for worst air quality in Cook County history.
The conditions led the Chicago Park District to close all beaches and outdoor pools, and events like a Chicago Fire home game were postponed due to the hazards.
Conditions improved by Friday afternoon before devolving again starting late Saturday.
Sensitive groups, including children, the elderly and those with lung disease like asthma, should avoid long or intense outdoor activities and move indoors if possible, while everyone else should reduce long or intense activities outside on Friday, according to the agency. Those who must be outside are encouraged to wear a proper-fitting N95 or KN95 mask.
