Winter break got a little longer for thousands of students as Gov. Mark Dayton took the rare step of canceling school statewide on Monday, with temperatures predicted to plunge to 25 to 35 degrees below zero across Minnesota that morning.

"The safety of Minnesota's schoolchildren must be our first priority," Dayton said Friday. "… I encourage Minnesotans of all ages to exercise caution in these extreme weather conditions."

Although the state is used to frigid winters, this predicted deep freeze surpasses even what hardy Minnesotans can handle. The National Weather Service is forecasting windchills of 60 degrees below zero Monday morning in northern and central Minnesota and 50 below in the Twin Cities and south.

In addition to the schools closing, the weather was prompting other cancellations across the state — from Sunday church services to parks programs to recycling pickup.

3M Co. sent an e-mail to employees at its Maplewood campus telling them they should stay home Monday rather than report to work.

At least one college, the University of St. Thomas in St. Paul, announced that it would be open only for essential employees on Monday. In Wisconsin, Gov. Scott Walker was reported to be considering canceling school on Monday, as well.

For the most part, local school officials in Minnesota applauded the decision to cancel classes Monday. Many were already contemplating the move, concerned about the weather's effect on students waiting for buses or walking to school.

"When you're talking about a windchill of 30 to 40 degrees below zero, you just don't want kids outside," said Rick Kaufman, a spokesman for Bloomington Public Schools.

While Dayton's announcement applied only to public schools, including charters, private schools also said they would be closed Monday. In the Twin Cities, for example, Minnehaha Academy, St. Paul Academy, Cretin-Derham Hall, Blake, Holy Angels and Annunciation School in Minneapolis all posted online announcements of Monday closures.

The gravity of such subzero cold was underlined in a report from New Ulm, where William Harry Lee, 79, was found unresponsive in his back yard late Thursday. He had fallen, but the 18-below temperature contributed to his death, according to the Brown County coroner.

3 cold closures in '90s

Canceling classes statewide because of the temperature is extremely rare.

Gov. Arne Carlson made front-page news on Jan. 18, 1994, by doing so when windchills in some areas plunged to 80 degrees below zero under the measure used at the time (the formula has since been changed).

Carlson also called off classes on Feb. 2, 1996 — the day the state saw its all-time low temperature of 60 below zero near Tower, Minn., and the Twin Cities dropped to 32 below.

Carlson canceled schools for a third time on Jan. 16, 1997.

At the time, some complained that local school officials, not the governor, should make that call. On Friday, students applauded Dayton's decision, posting photos on social media that showed them dancing in celebration while urging the governor to run for president of the United States.

Many parents also supported the call, but some were concerned about trying to find child care on Monday.

"I know a lot of parents who don't have child care," said Marian Johnson, an Edina parent. "They have to worry if they can get the day off."

State Education Commissioner Brenda Cassellius said local school districts — not the state — will decide whether to open on Tuesday.

She explained that school officials typically like to wait until the weather forecast is as accurate as possible before making a decision. But in this case, as most districts were coming off a two-week holiday break, state officials felt comfortable calling off school days in advance.

The early warning, Cassellius said, should give parents time to make child-care arrangements.

"We take these things very seriously," she said. "It was not a decision made lightly."

Congealed bus fuel

Already, the low temperatures were causing problems for some Minnesota schools where classes had resumed Thursday.

At Dilworth-Glyndon-Felton in the northwestern corner of the state, two buses were delayed when their fuel congealed, a phenomenon that can strike when temperatures drop to 20 degrees below zero.

"It was a perfect storm of events," said Superintendent Bryan Thygeson. "It was a cold day to start with — about 27 degrees below zero when the buses started running — and our first day back to school."

Some school officials as well as the state teachers' union urged students to stay inside, read and catch up on homework on Monday.

Zoo not an option

Whatever parents ultimately decide to do with their kids on Monday, it won't involve taking them to the Minnesota Zoo.

Zoo officials cited Dayton's decision to cancel classes in announcing that the Apple Valley operation would be closed on Monday.

"The safety of our guests is always our first priority," said Zoo Director Lee Ehmke.

The Associated Press contributed to this report.

Kim McGuire • 612-673-4469

Rachel E. Stassen-Berger Twitter: @RachelSB