A windchill warning is in affect across for most of Minnesota, western Wisconsin and parts of North and South Dakota through noon Thursday, the National Weather Forecast said. Overnight temperatures across Minnesota dipped to 30 below in Park Rapids, 27 below in Bemidji and 12 below in the Twin Cities.

“We are now looking at the weather and the windchill warning from the U.S. Weather Service,” Anoka Hennepin spokeswoman Mary Olson said Wednesday afternoon. “When it says frostbite can occur in five to 10 minutes, that makes us concerned for student safety.”

Many schools that didn’t close were expected to start late, and several canceled extracurricular activities.

While temperatures are expected to rise Friday, an unrelenting string of subzero temperatures, clouds, lots of wind and snow isn’t close to letting up.

With even colder temperatures predicted through the end of the month, Minnesota is on pace to have its coldest January in 33 years, said Mark Seeley, a University of Minnesota climatologist who publishes a weekly weather newsletter.

“Gosh, you have to say that we’ve been predominantly wimpy in the wintertime. Since 1982, we’ve had very few occurrences like this month,” he said.

What’s really bugging Minnesotans, he said, is that the cold just won’t let up, with few days in the 20s or 30s.

“It’s really stressing us out because it’s been so persistently cold, with relatively little sunshine,” Seeley said.

The fluffy snow is coveted by cross-country skiers, snowmobilers and other winter-sports enthusiasts, he said, but it also means shoveling and snowblowing and trying to stay on the roads.

“The snow on the landscape has been so persistent that we’ve had to close roads because it blows around,” he said. Even when there’s not a heavy snowfall, those high winds are sending the lightweight snow swirling and drifting, especially in rural areas with flat expanses, he added.

He pointed to repeated shutdowns of Hwy. 2 in the Red River Valley. On Wednesday, a 30-mile stretch of the road from East Grand Forks to Crookston was closed because of blowing snow. It reopened about 1:45 p.m., but gusty winds continued to affect visibility.

Amid windchill and blizzard warnings, icy roads and blowing snow contributed to hundreds of crashes in Minnesota on Wednesday.

Statewide, 385 crashes were reported by Wednesday afternoon, and, of those, 53 had injuries, the State Patrol said. Another 300 drivers needed help after going off the road or spinning out, the patrol said.

Part of the problem is that the extreme cold causes “black ice,” which is difficult to see.

The cold also reduces effectiveness of salt in melting snow and ice off the roads, said Kent Barnard, a spokesman for the Minnesota Department of Transportation.