Clouds gradually clear to a mostly sunny stretch through Monday.Hot, humid conditions arise later next week, plus the threat of strong to severe thunderstorms and soaking rain.Tonight: Few clouds with ...

Smoke from Canadian wildfires again plagued portions of the northern United States on July 16, prompting air quality alerts from Illinois to Maine.

Wildfire smoke is an environmental pollutant that impacts large regions, making it a true population-level hazard.