Extreme heat will continue to harass Minnesota through Thursday

A NEXT Weather Alert remains in effect through Thursday evening, as does an extreme heat warning.

Tuesday through Thursday, expect highs in the 90s and heat index values near 100. The sweltering heat has caused North America's largest youth soccer tournament — the Target USA Cup in Blaine, Minnesota — to add additional safety measures. 

In northeastern Minnesota, a red flag warning will again be in effect Tuesday due to critical fire weather conditions. All entry points to the Boundary Waters Canoe Area Wilderness will be closed this week as wildfires burn in the area. On Sunday, Gov. Tim Walz declared a peacetime emergency and mobilized the National Guard to aid in battling the fires.

Temperatures will ease slightly as we head into the weekend, with highs in the upper 80s and lower 90s.

Early next week, a system may bring the next opportunity for showers and storms.

Air quality alert

The Minnesota Pollution Control Agency has issued an air quality alert Tuesday that's in effect through Friday at 11 a.m. — but the agency says it may be extended.

The alert spans communities including the metro, Alexandria, Brainerd, Duluth, Ely, Hibbing, Hinckley, International Falls, Moorhead, St. Cloud, Two Harbors, Winona and the tribal nations of Fond du Lac, Grand Portage, Leech Lake, Mille Lacs, Prairie Island, Red Lake and White Earth.

The agency says "very heavy smoke" from fires in the Arrowhead, the BWCA and southern Canada will quickly inundate much of the state with the help of a sagging front that will dray the air down south.

The smoke will reach across northern and central Minnesota by early Wednesday, and arrive in the metro and southeastern Minnesota by Wednesday evening.

That smoke could block enough incoming solar radiation to knock high temperatures in the state back a few degrees. So perhaps cooler, but filthy air.