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

Multiple U.S. states and Canadian provinces are experiencing poor air quality from wildfire smoke. Here's where.

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.