A bitter blast of winter weather blew across much of Minnesota on Sunday afternoon, canceling most school classes for Monday. The cold snap also left many residents shivering, as utilities urged customers to dial down their thermostats to conserve natural gas put in short supply by a Canadian pipeline explosion.

Anoka-Hennepin schools became the first metro-area district to call off Monday classes, followed shortly by Minneapolis and St. Paul. Officials in Rochester and Winona had made the call to cancel earlier in the weekend, and by late Sunday, as windchills headed toward 50 below zero, most metro districts had joined the list of schools that will be closed Monday. Classes at the University of Minnesota also were canceled.

Dangerous windchills will persist into Tuesday, forcing administrators to confront more cancellations.

Even as temperatures plunged Sunday, Xcel Energy asked all customers, including in the Twin Cities, to cut back on natural gas use in the wake of Saturday's pipeline blast near Winnipeg, disrupting supplies of natural gas service for more than 100,000 Xcel customers in northwestern Minnesota, eastern North Dakota and western Wisconsin. On Saturday night, Xcel officials asked customers in those areas to keep home thermostats at 60 degrees.

On Sunday afternoon, they expanded the request to all residential customers. CenterPoint Energy did not ask its ­customers to cut back gas use.

The fourth day of canceled classes at most schools since Jan. 6 is taking a toll on parents and teachers and raising questions about whether the days will need to be made up in June or during spring break.

But safety, school officials said Sunday, comes first.

Severe windchills can cause frostbite to occur in five to 10 minutes, said Mary Olson, a spokeswoman for Anoka-Hennepin schools. "We have students that walk up to a mile to school, and for a little first- or second-grader that's probably at least a 15- to 20-minute walk. And kids wait for the bus for up to 10 minutes. If there's a delay … we just don't want to risk students having frostbite."

Schools have not yet decided if and how they will need to make up days.

"We are sincerely hoping it's going to warm up," Olson said. "This has been really frustrating."

Toya Stewart Downey, spokeswoman for the St. Paul public schools, echoed that sentiment Sunday.

"This is just January," she said. "We still have two months of winter left."

After Monday, she said, the St. Paul district will have just one more free day available and would have to consider makeup days. Edina schools warned parents Sunday that makeup days are likely.

Family budgets whacked

After bringing her daughter to Farview Recreation Center in north Minneapolis on Sunday, Melinda Blevins planned to stock up on groceries.

"We're on the free lunch program, so my concern is making sure my kids are fed," Blevins said. "This adds extra expense."

The Minneapolis Park and Recreation Board will keep recreation centers open extra hours on Monday because school is canceled."I see kids in the neighborhood who don't have adequate winter clothing — no hats, no gloves and sometimes no jacket," said Hanna Esparza, a front-desk worker at the Powderhorn Park Recreation Center. "It's dangerous."At Chisago Lakes High School in Lindstrom, Minn., math teacher Lindsey Wilson lamented the fact that her students are missing important learning days."Canceling school is a pain for everyone," Wilson said. "Nobody wants to go into June, but what are the options? Some students don't have proper winter gear, especially for dangerous windchill temps. Safety comes first."

School cancellations also are affecting families who rely on private child care services. Child Garden Total Environment Montessori closes in tandem with Minneapolis public schools.

In an e-mail to parents, the Montessori's director, Hannah Nelson, explained the decision to close: "I know that our children are not waiting at bus stops and such, but in this weather, it is advised that no children under the age of 5 are outside for any reason. Also, many of our staff members walk or bus to work."

The school has offered makeup days to paying parents, but that's little consolation to Chris Voss, who has had to miss work to stay home with his two children.

"I'm trying to figure out if this weather is really extraordinary or if we've become more sensitive as a culture," Voss said. "The whole reason for day care is so that we can work, so this is very disruptive to our professional lives."

MnDOT closes highways

High winds and blowing snow began wreaking havoc with travel and other activities in western Minnesota on Sunday.

White-out conditions forced the closure of Hwys. 2 and 11 in northwestern Minnesota and Hwy. 15 in the central part of the state. A 10-vehicle accident closed a stretch of the north- and southbound lanes of Hwy. 15 from St. Augusta to Kimball on Sunday afternoon, a Stearns County dispatcher said.

The Minnesota Department of Transportation closed Interstate 94 from Moorhead to Alexandria; Hwy. 10 from Detroit Lakes to Moorhead, and Hwy. 210 from Fergus Falls to Breckenridge. The North Dakota Department of Transportation closed 190 miles of I-94 from Fargo to Bismarck and Hwy. 83 from Bismarck 110 miles north to Minot.

State officials warned motorists in rural areas to travel only if absolutely necessary, a caution echoed by metro traffic officials as the winds swept into the Twin Cities. By 2 p.m., road conditions were becoming treacherous, with wind gusts over 40 miles per hour reported at Minneapolis-St. Paul International Airport. Meteorologists said temperatures could hover around minus 20 degrees early Monday morning with windchills near minus 50.

The frigid weather and biting wind also led St. Paul Winter Carnival officials to close its giant slide until Tuesday.

Pipeline blast

Xcel Energy officials said Sunday that customer conservation efforts Saturday kept the utility from running out of natural gas for some customers.

"We want to thank our customers for the assistance they are providing by reducing the temperature in their homes," Kent Larson, Xcel's senior vice president for operations, said in a statement Sunday that extended the conservation request to all customers. "This has helped our system remain stable through the night and morning hours. We ask them to continue conserving natural gas until the situation is resolved."Late Sunday one pipeline returned to service and Xcel continued getting natural gas from the Twin Cities area and Michigan to serve its areas in northwestern Minnesota, North Dakota and Wisconsin.

Staff writers Chris Havens, Pat ­Pheifer and Anthony Lonetree contributed to this report. Aimee Blanchette • 612-673-1715