Chicago’s Air Quality Among The Worst In The World Once Again As Wildfire Smoke Returns

Chicago's air quality worsened to 'unhealthy' levels due to Canadian wildfire smoke, with an Air Quality Index (AQI) of 134. The city ranked second worst globally for air quality at one point, surpassing cities like Minneapolis and Detroit. An air quality alert remains in effect, and past conditions had broken Cook County's AQI record at 638.