The U.S. Postal Service announced late Tuesday afternoon that deliveries and other services in Minnesota and several other states will be suspended Wednesday in the wake of a deep freeze unmatched for nearly a quarter-century.

The National Weather Service (NWS) is forecasting a high of minus-17 in the Twin Cities on Wednesday, with windchills tumbling to the minus-50s.

Also Tuesday night, Xcel Energy was reporting 90-plus outages in the southwest metro that was knocking out power to more than 6,500 customers.

The halt in postal services covers not only Minnesota but Iowa, western Wisconsin, western Illinois, North Dakota, South Dakota, eastern Montana, and portions of Nebraska, Missouri and Kansas.

The cold reality of the conditions defies the Postal Service’s longstanding, albeit unofficial motto: “Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds.”

The suspension also includes mail pickup from businesses and collection boxes, and no pickup of packages from residences and businesses.

Retail counter service in the affected areas will be available “but may be limited” in ways the Postal Service did not specify.

Mail carrier Scott McLaughlin, whose Minneapolis route covers the Lowry Hill neighborhood, said Tuesday night that he appreciates the Postal Service cancelling deliveries, but “it’s hard for me to be grateful. Tomorrow is my day off on the schedule.”

McLaughlin said Tuesday’s trudge was brisk as “the wind steadily grew throughout the day.”

Thermometers digital and employing mercury continued to plummet Tuesday as Minnesota headed into one of its deepest freezes in decades. With windchills that will make it feel like -40 degrees in Minneapolis by sunset and colder outstate, Minnesota is hunkering down.

In addition to schools closing, including the University of Minnesota, events are being canceled and some businesses are shutting down early.

For example, Lunds, Byerly’s and Kowalski’s grocery stores announced they will close at 7 p.m. Tuesday and Wednesday for the safety of their employees while some grocery delivery services announced they won’t be sending their drivers out on Wednesday.

Even hearty Minnesotans know when to come in from the cold when it gets dangerous. Major ski hills throughout Minnesota closed Tuesday — Afton Alps, Buck Hill, Welch Village, Spirit Mountain and Lutsen. Ice Castles in Excelsior will be closed Wednesday and Thursday.

With the bitter cold getting a firmer grip, other closures multiplied Tuesday. The Minnesota History Center announced it would close at 5 p.m. instead of at 8 p.m. on Tuesday and canceled all evening programs. Several well-known historic sites — including Mill City Museum, the James J. Hill House and Split Rock Lighthouse — announced they would be closed on Wednesday.

In a Tweet, Surly Brewing announced it would close at 8 p.m. Tuesday, stay closed Wednesday because it’s just too cold and reopen at 11 a.m. Thursday. “Layer up and don’t do anything dumb,” the brewry posted.

With some not wanting to venture out in the cold, HAUS Salon in Minneapolis offered to pay for an Uber or Lyft ride for their clients and employees on Wednesday.

With Minneapolis schools closed Tuesday, snacks and/or meals were offered at some parks and libraries. And in the Twin Cities, Lyft is offering free rides to warming centers through 11:59 p.m. Friday. For a free ride, up to $25 a ride, use the code MSPJAYDEN19.

In neighboring Wisconsin, Gov. Tony Evers declared a state of emergency, because of the snow and and the dangerous cold temperatures settling over much of the Upper Midwest. Evers activated the Wisconsin National Guard to assist with local responders if necessary.

Temperatures began plummeting after hitting a high of only minus 3 degrees at midnight, said Brent Hewett, meteorologist at the National Weather Service in Chanhassen. By noon, with the help of the sun, it hovered around minus 8 but a northwest wind made it feel like minus 33 degrees. But as the sun slips closer to the horizon, the temperatures will fall to about minus 15 degrees. Combine that with a 20 to 25 mph wind, and it will feel like a numbing 40 degrees below zero.

But hold onto your hats and blankets — it will feel even colder by Wednesday morning with stronger winds, racking up a windchill of minus 50 in the Twin Cities, Hewett said. And that’s in the warmer urban core. It will be even colder outside the city limits, he added.

Northern Minnesota already was feeling the sharp sting of the brutal cold. By 1 p.m. Tuesday, Duluth residents were already feeling numb with a winchill temperature that made it feel like minus 42. Northern Minnesota likely will lead with the coldest air overnight with windchills that register minus 53 in Duluth, minus 64 in International Falls and minus 67 in Walker.

Postponements of high school athletic contests, whether inside or out, are piling up across Minnesota, following suit with academic instruction put on hold in what could be called Winter Break 2.0. The University of Minnesota and other colleges, which usually have a higher bar for suspending learning, also got into the act.

The University of Minnesota shut down its Twin Cities campus at 5 pm. Tuesday and will reopent at noon on Thursday. Only employees deemed critical to the health and safety of the campus will be required to report to work.

Among the games called off for Tuesday night is the marquee event in boys basketball pitting No. 1 teams, Hopkins in Class 4A and DeLaSalle in 3A.

Thinking about attending Tuesday night’s open house in Maple Grove ahead of major construction along Interstate 94 on that side of town? It’s been rescheduled for Feb. 7 at the Maple Grove Government Center because of the cold.

The mercury in the thermometer is expected to fall to minus 29 Tuesday and Wednesday night, according to the National Weather Service. And then the winds die down and Minnesota will eventually thaw. Thursday’s high temperature will hit minus 3, climb to 13 degrees on Friday and hit an almost balmy winter temperature of 38 degrees on Saturday.

In the meantime, officials warn people to be careful out there.

Traffic Tuesday morning was as brutal as the subzero temperatures brought black ice that sent motorists skidding into medians and ditches, and in all too many cases, each other.

A multicar crash about 6 a.m. on westbound Hwy. 610 near Hwy. 169 in Brooklyn Park and a simultaneous wreck farther east on the Mississippi River bridge had traffic parked back to University Avenue in Blaine. And that was just the start of the commuting misery as tow trucks and law enforcement were put to their paces as incidents littered metro area highways and freeways.

Problematic spots during the morning commute included southbound Hwy. 100 through Robbinsdale and Golden Valley where numerous wrecks strangled traffic, eastbound Hwy. 10 through Anoka and Coon Rapids and Interstate 35 in both directions through Lakeville.

The smashing and crashing didn’t stop with the end of the morning rush hour. At 10:15 a.m., MnDOT was reporting more than a dozen spinouts and wrecks across the metro area, including a pair of spinouts on northbound Hwy. 61 at Jamaica Avenue in Cottage Grove and northbound I-35W at Hwy. 36 in Roseville.

Can’t overlook dangers

On the most serious of notes, there has been at least one death attributed to the extreme cold. A man found outside a home early Sunday in Rochester may have succumbed to bitterly cold weather, although authorities are awaiting autopsy results before confirming the nature of Ali Gombo’s death. The 22-year-old was found on the back deck of his sister’s house, where he had been living, according to police. Authorities said Gombo was dropped off near the house but did not have keys to the residence.

As part of the effort to keep people safe and warm, homeless outreach workers in Minneapolis have been rushing to equip people living outside with warm clothing. A number of shelters in Minneapolis and St. Paul also announced they would remain open around the clock.

Staff writer Tim Harlow contributed to this report.