The Air Quality Index (AQI), a system used to communicate how much pollution is in the air, is expected to reach the red or unhealthy category in a large swath of Minnesota, and will likely remain so through Saturday.

At the Minnesota Pollution Control Agency (MPCA), most of Minnesota was classified as having “moderate” air quality late Sunday morning, with areas around Marshall, Moorhead and Hibbing being a potential risk for people with breathing sensitivity. An air quality alert for Minnesota through Monday issued by the MPCA remains in effect.

An air quality alert covering the entire state of Minnesota continues on Thursday, marring otherwise fairly ideal weather conditions.