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

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

Milwaukee, Ozaukee, Racine, Kenosha and Sheboygan are all under a poor air quality alert from noon to 11 p.m., according to ...

Additional plumes of smoke from Canada's active wildfires prompt officials to issue a statewide air quality alert on July 14.