Chicago air quality is at an unhealthy level for many, especially sensitive groups, as smoke from the Canadian wildfires is blown in by winds from the northwest.

Wildfire smoke was helping raise ozone to hazardous levels. No alerts have been issued, but the air quality may approach “code orange” levels again late Thursday afternoon in parts of the region, as it appears that the ozone factory will still be operating while the Canadian wildfire smoke persists in the skies over Philly.