In this map from the MPCA for this week, Canadian wildfire smoke could reach southern Minnesota by Thursday.

A Canadian wildfire burning near Lake Winnipeg is responsible for the Minnesota Pollution Control Agency predicting another “significant” air quality event for southern Minnesota Thursday. The wildfire smoke was already impacting the northern part of the state on Tuesday.

By Thursday, air quality in the southern half of the state is predicted to be unhealthy for sensitive groups, including children, senior citizens, pregnant women, and those with heart or respiratory conditions.

The MPCA states smoke concentrations could rival what was observed in July/August 2021 in Minnesota, when the state experienced a thick haze and smoky odors for more than a week.