The National Weather Service said the alert will be in effect until Sunday morning in the Santa Clarita Valley and Saturday night in parts of Los Angeles, Ventura, San Bernardino, and Riverside counties.

The red alert, issued by the Minnesota Pollution Control Agency, means that the air quality is unhealthy for everyone. It will begin at 9 a.m. Sunday and last until 9 a.m. Tuesday, Aug. 12, for large portions of the state, including the Minneapolis-St. Paul area.

As Canada grapples with one of its worst wildfire seasons on record, smoke from the blazes have prompted air quality alerts across the U.S.