Wildfire smoke degrades air quality in swaths of Ontario, with Toronto ranking among the worst in the world on Monday.

Smoke from wildfires in Manitoba, a Western province facing its worst fire season in 30 years, has created hazardous air quality conditions across Eastern Canada and the United States.

The extended forecast suggests unsettled weather midweek, with rain probabilities ranging from 30% to 60%. There is some uncertainty about the exact timing and placement of the rain, but meteorologists anticipate widespread cloud cover and precipitation potential Wednesday through Thursday.