Canadian wildfire smoke chokes upper Midwest for second straight year

Smoke from Canadian wildfires has prompted health warnings across the upper Midwest for the second straight year. Smoke from fires burning in British Columbia and Alberta had settled over parts of Montana, the Dakotas, Minnesota and Wisconsin by Monday morning. The Minnesota Pollution Control Agency on Sunday issued its first air quality alert of the season for the entire state. The agency said pollution levels will be unhealthy for everyone before the warning expires Monday afternoon. The Wisconsin Department of Natural Resources issued health advisories for multiple counties across the state's northern two-thirds. The National Weather Service said smoke could reach as far south as Iowa and Chicago by late Tuesday.