MINNEAPOLIS (WCCO) – The Minnesota Pollution Control Agency has extended a code orange air quality alert for northern Minnesota and areas of the Red River Valley through Saturday at noon.

The alert was originally set to expire Friday, but MPCA says the smoke conditions will not improve enough until Saturday afternoon to be out of the orange category.

MPCA is concerned about smoke pooling in the Red River Valley. The alert was canceled near the shores of Lake Superior due to a lake breeze forming and pushing pollution away from Duluth, Two Harbors, and Grand Marais.

The orange category indicates that the air is unhealthy for sensitive groups, such as older adults and those with chronic respiratory conditions.

In the coming days the smoke will retreat but the persistent heat will allow for more ozone formation, according to the MPCA. Moderate air quality conditions will persist, along with a haze through the weekend.