The "unhealthy" air, which ranks as level four of six on the Air Quality Index, comes after multiple consecutive days of air quality alerts.

The National Weather Service has opted to extend an air quality alert in the Chicago area for another day.

The hazy skies in the Chicago area are the visible sign of the poor air quality Thursday as smoke from Canadian wildfires ...

The National Weather Service issued an air quality alert for the city on Thursday and kept extending it through Sunday night. There was no alert Monday.

National Weather Service officials called an air quality alert in effect until midnight as well as a beach hazard warning.

However, Lake, Porter, Newton and Jasper counties in Indiana will be under another air quality alert all day Tuesday. The ...

An air quality alert for the Chicago area was extended for a second time as smoke from Canadian wildfires lingers overhead ...

Smoke from Canadian wildfires continues to affect air quality across the Midwest, though Monday’s conditions were an ...

Air quality alerts issued Thursday in Illinois because of Canadian wildfire smoke marked the latest bout in an increasingly ...

Air quality will deteriorate across 12 states through Saturday, mainly in the Upper Midwest, as wildfire smoke pours into the ...

Wildfire smoke has pushed Chicago's air quality into the "unhealthy" zone. It's so bad, in fact, that we're the most polluted ...