Thursday’s frigid air and dangerous windchills led several school districts to tell students to stay home, while the National Weather Service warned people to limit their time outdoors.

But relief lies ahead, the NWS said, warning that Thursday night into Friday was still dangerous with windchills expected to be from -20 to -35. 

Arctic air that roared into the state Wednesday and overnight dropped windchill readings in the Twin Cities to 30 degrees below zero at 6 a.m., with readings of 40 degrees below zero or lower across a large portion of northern and western Minnesota. The coldest windchill reading was 48 below zero in Fosston in northwestern Minnesota, according to the NWS.

An actual temperature of -10 degrees in the Twin Cities at 5:45 a.m. Thursday tied for the coldest reading of the season, according to Minnesota State Climatology Office records.

Those readings were enough for the Anoka-Hennepin School District to call off classes Thursday “due to extreme winter weather conditions in the early morning hours,” a notice on the district’s website said.

Other districts, including Little Falls, Osseo, St. Cloud and St. Francis called off classes. In Elk River and Cambridge-Isanti, students will have an e-learning day, meaning instruction will be delivered online.

Minneapolis and St. Paul schools were open Thursday. Windchills must drop to -35 degrees for Minneapolis schools to close.

Friday will be a bit warmer, with a high of 18 forecast for the Twin Cities under sunny skies. Temperatures will gradually rise overnight Friday. And a thaw is in store for the weekend with highs reaching 34 degrees on Saturday before dropping into the 20s most of next week.