Wildfire Smoke Drives Chicago Area Air Quality to Hazardous

A thick, hazardous haze from Canadian and Minnesota wildfires blanketed the Chicago metropolitan area and parts of Wisconsin on Thursday, July 16, 2026, triggering widespread air quality alerts and forcing the closure of public beaches, pools, and summer camps. Air quality readings reached historic, dangerous levels across the region, with officials urging all residents to limit outdoor exposure.

The National Weather Service issued an air quality alert for nearly all of the Chicago area, extending into northwest Indiana and Kenosha County, Wisconsin, which remained in effect through Thursday night. Particulate matter levels soared into the "very unhealthy" and "hazardous" categories on the Air Quality Index (AQI), a scale of 0 to 500. In northern Cook and Lake Counties in Illinois and Kenosha County, Wisconsin, AQI values exceeded 300, entering the hazardous, or maroon, level. Specific readings were stark: Lake Forest, Illinois, reached 428; Gurnee hit 446; and Zion climbed to 558. Across the border, Milwaukee recorded an AQI of 566, which officials said was nearly double its previous record set in 2023.

Meteorologists noted the severity was unprecedented for the area, with one...