According to forecasters at AccuWeather, cities where smoke is expected to become thick enough to be noticeable include Fargo, North Dakota; Minneapolis and Duluth, Minnesota; Green Bay and Milwaukee; and Chicago, Illinois. Additionally, high-altitude wildfire smoke may be visible as far southeast as Detroit and Indianapolis.

States across the border issued air advisories about particulate pollution that are expected to last for several days.

Authorities in Manitoba, which shares a border with the U.S., issued a state of emergency. Winds will likely blow wildfire smoke into Midwestern states.