Triple-digit temperatures were expected to break records across parts of the Northern Plains on Wednesday. Forecasters warned strong winds could stoke out-of-control wildfires, and said the dangerous conditions will sweep into the central Plains by Thursday.
The National Weather Service warned of "extremely critical" fire conditions across 22,600-square-miles in northern Montana including the cities of Great Falls and Havre.
RECORD HEAT BAKES CALIFORNIA, HIGH PLAINS, WITH SOME RELIEF COMING
By afternoon temperatures were forecast to hit 104 degrees Fahrenheit in Billings and 105 degrees in Sheridan, Wyoming.
The high temperatures, wind gusts of up to 60 miles per hour and tinder-dry fuels mean fires could spread rapidly.
MONTANA FILES LEGAL CHALLENGE AGAINST BIDEN ADMIN OVER PLANS TO TAKE LAND OUT OF PRODUCTION
Portions of western Montana, Oregon, northern California, Idaho and Washington state also had critical wildfire danger.
The risk will shift to the south and east Thursday. Fire warnings were issued for areas of South Dakota, Nebraska and Idaho.
Nearly 54 million people were under heat warnings and advisories across the West as temperature records were shattered in many areas.
HIGH WILDFIRE DANGER HITS MONTANA AMID EXTREME HEAT
Relief was nearing for parts of the region: A fast-moving cold front out of the Canadian Rocky Mountains was expected to drive down temperatures to well below average by Friday.