Parts of Canada are seeing some of their most unhealthy air yet, and the smoke is likely to move over the United States again this weekend.

A Chicago Air Quality Alert has been extended through Friday as smoke from Canada wildfires has pushed the AQI into unhealthy levels across the region.

Parts of the Greater Toronto Area and surrounding communities are under a special air quality statement Friday morning as wildfires scorch Manitoba, Saskatchewan and Alberta. Wildfire smoke is causing or expected to cause poor air quality and reduced visibility,