MADISON, Wis. (AP) — Smoke from Canadian wildfires has prompted health warnings across the upper Midwest for the second straight year.

Fires raging in British Columbia and Alberta sent the haze over parts of Montana, the Dakotas, Minnesota and Wisconsin on Sunday, lingering into Monday morning.

The Minnesota Pollution Control Agency issued its first air quality alert of the season for the entire state on Sunday. The agency said pollution levels will be unhealthy for everyone. The agency urged people to remain indoors and avoid heavy exertion outdoors until the warning expired at noon on Monday.

The Wisconsin Department of Natural Resources issued advisories for multiple counties across the state’s northern two-thirds on Sunday, warning that air quality is unhealthy for sensitive people. The advisories were set to end at noon on Monday as well.