Temperatures crashed to record lows well below zero Monday as a huge mass of arctic air blustered southward across the Midwest and West, keeping people indoors and leading some cities to open shelters.
The cold and remnants of the weekend blizzard that accompanied it closed hundreds of schools from the northern Plains into the Great Lakes states.
The St. Francis House shelter for the homeless in Sioux Falls, S.D., where Monday's low was 11 below zero, was a lifesaver, said Richard Byrd.
"I would be probably huddled up right now under a bunch of blankets because this was my only alternative. If it wasn't for the St. Francis house, I'd be in a scary, scary situation," he said.
Major highways in northern and western Minnesota and wide areas of North and South Dakota had reopened after Sunday's blizzard dropped as much as 14 inches of snow, but hundreds of schools were closed in the three states.
Monday morning lows in North Dakota included 25 below zero in Dickinson and Williston and meteorologists said the wind would make it feel like more than 40 below Monday.
Minnesotans claim to be accustomed to such weather. "It's not so bad; I actually kind of like it," Rory Strange of Duluth said as ice crystals covered his eyebrows after he spent a couple of hours clearing snow off his sidewalk and helping neighbors.
But in Williston, N.D., where the wind chill hit 25 below early Monday, Penny Groth acknowledged: "It's just darn cold right now." She said the Gramma Sharon's Family Restaurant she owns had been closed since Saturday night because of the snow and cold.
Monday's cold was an abrupt change for many areas. Illinois had unseasonable warmth Sunday with temperatures in the 50s, but Monday morning lows were in the single digits across the northern part of the state. Rockford had a low of just 3, and 20 mph wind made it feel like 18 below zero, the National Weather Service said.
Hundreds of Illinois schools were closed because of ice-covered roads. More schools were closed in Michigan, where northern sections had blizzard conditions as wind gusting to more than 50 mph caused whiteouts and generated wind chills as low as 30 below zero.
Thermometers read 31 below Monday in Glasgow, Mont., and the wind chill was 45 below, the weather service said. The Texas Panhandle had lows in the single digits and Goodland, Kan., registered a record low of 10 below zero.
Even western Washington state had freezing temperatures and the city of Seattle opened severe weather shelters for the homeless.
Other record lows Monday included 19 below zero in Denver, where the previous Dec. 15 record of minus 6 was set in 1951; and minus 16 at Sidney, Neb. Havre, Mont., registered a record 33 below Sunday, the weather service said.
The leading edge of the advancing cold air kicked off snow flurries as far south as central Arizona and the Texas Panhandle. Ski resorts around Lake Tahoe welcomed about a foot of snow that fell at higher elevations of California's Sierra Nevada, and some mountain pass highways were closed in Washington. Heavy rain threatened mud slides in southern California.
Numerous schools were closed in Oregon, where the snow made roads so slippery Sunday that chains were required in the Portland metro area. "We don't normally do that," said Dave Thompson, Oregon Department of Transportation spokesman. "That's how serious it is."
The weather service posted winter storm warnings Monday for parts of California, Nevada, Utah, Colorado, northern Arizona, New Mexico, Kentucky and Tennessee.
One person died in a wreck on a wet Southern California highway, and authorities in Colorado said a Ski Patrol member was found dead after a weekend avalanche outside the Aspen Mountain ski area.