Chicago experienced some of the worst air quality globally on Thursday due to Canadian wildfire smoke. The National Weather Service issued a red air quality alert, unhealthy for everyone, urging precautions like limiting outdoor activities. The alert was extended through Friday. Health officials advised sensitive groups, such as those with heart or lung conditions, children, and the elderly, to take extra care. The Illinois EPA declared an Air Quality Action Day, its first of 2025, encouraging pollution reduction and awareness. Air quality is expected to improve by Saturday.

Prepared by Olivia Bennett and reviewed by editorial team.