An air quality index of 300 or higher is considered hazardous, and the record-breaking smoke AQI in Grand Portage reached 800 on Tuesday.

The Minnesota Pollution Control Agency says additional air quality alerts are likely needed for much of Minnesota this weekend due to the heavy wildfire smoke in Canada moving into the upper Midwest.

From Sunday to Tuesday, smoke in northwest Canada swirled into the northern Plains, giving Minnesota some of the worst air quality in the world.