Students in Minnesota’s largest school districts are getting another chance to chill, with classes being canceled for Tuesday because of the persistent deep freeze.

The Anoka-Hennepin district made the announcement early Monday afternoon, giving families plenty of time to adjust their schedules. Other large districts on Tuesday’s no-go list include: Bloomington, Minneapolis, Osseo, Richfield and St. Paul.

“We are aware families are growing tired of these repeated arctic air masses and their impact on school,” the Bloomington district posted on its website. “However, severe weather temperatures are expected to be nearly -20 combined with windchills of -40 or lower, which could cause frostbite within 15 minutes of exposure. We want to keep students in school, but safety for all our students is our top priority.”

Most every school in the state, including the University of Minnesota and several other colleges, called off classes Monday as daybreak temperatures were in the teens and 20s below zero from one border to another.

As for how to keep warm, concerns about the supply of natural gas to much of frigid Minnesota eased Monday, with a major utility returning to normal operations.

Xcel Energy urged customers Sunday to dial down thermostats to conserve natural gas that was in short supply because of a pipeline explosion near Winnipeg. By Monday morning, however, Xcel Energy reported improved flow from the TransCanada pipeline into Minnesota’s service provider, which is allowing the utility to lift its conservation request in stages.

Double digits below zero was the norm throughout the Twin Cities area before and soon after sunrise, according to the National Weather Service. Lakeville was the lowest of the metro low at 8 a.m. at minus-18. With the wind, that meant it felt more like 44 below.

Elsewhere in Minnesota just before dawn: minus 26 in Grand Marais and the wind made it feel like 53 below. Then there was 26 below actual temperature way up there in Crane Lake and Fosston, and minus 24 in Park Rapids and Staples. Madison only had to put up with 8 below.

Some schools in session

While schools by the hundreds were absent the pitter-patter of knowledge-starved occupants Monday, Cretin-Derham Hall, a Catholic school in St. Paul, merely delayed classes until shortly after 9 a.m. Monday.

One large district in the midst of the winter mayhem, Moorhead, toughed it out and opted for a two-hour late start. International Falls did the same.

Despite the closures lessening Twin Cities traffic, black ice and snow-covered ramps and overpasses led to scores of crashes and spinouts during the morning commute. At least seven rollovers were reported between 5 and 7 a.m. on metro freeways.

Motorists on southbound Interstate 35W heading toward the urban core suffered the most, with crashes at County Roads C and D in Roseville just after 7 a.m. creating near gridlock conditions from Lake Drive in Blaine past the scene.

At 7:30 a.m., several vehicles spun out and blocked traffic on inbound I-94 at Broadway in Minneapolis.

Also, there’s a stall on the state’s 511 road information system, and callers are being detoured to 1-800-542-0220. No word on whether extreme cold played a role.

The choo-choo blues

Train riders also experienced delays. The frigid cold caused switches on the tracks in Elk River to freeze, prompting a 30-minute delay for the first inbound Northstar train. That train was also delayed on its northbound run back to Big Lake, and a subsequent trip back into Minneapolis was canceled.

Metro Transit used express buses to transport riders who normally catch the final inbound Northstar train from stations in Elk River, Anoka, Coon Rapids, Ramsey and Fridley to downtown Minneapolis. All afternoon trains are expected to run as normal, a transit spokesman said.

So much snow piled up on the light-rail tracks at 24th Avenue in Bloomington that Metro Transit suspended Blue Line service between the Mall of America and the Humphrey Terminal 2 Station at the Minneapolis-St. Paul International Airport for about 90 minutes. Buses filled in until service cranked up again about 8:40 a.m.

Tough to call them highs, but the Twin Cities area will get no warmer than the upper single digits below zero Monday, then free-falling to at least 20 below Monday night into Tuesday morning.

From there, maybe 0 on Tuesday for the metro, a teasing high of 24 on Wednesday, then back down to no better than 9 on Thursday.

Windchill warnings were expected to remain in effect through midday Tuesday for the Twin Cities area and across southern Minnesota.

Wind gusts reached 60 mph Sunday in Redwood Falls — the highest in the state. Elsewhere, gusts registered at 58 in New Ulm, 54 in Morris, 53 in Mankato, 51 in Hutchinson and 49 in St. Paul.

Bitter cold and dangerous winds weren’t enough to cancel two Minnesota outdoor sporting events for endurance athletes.

The 30th John Beargrease Sled Dog Marathon kicked off Sunday in Duluth with 30 mushers and 420 dogs racing at 374-mile course up the North Shore and back. The Arrowhead Ultra 135 race began Monday in International Falls.