Another day of frigid wind chills and brutal cold across much of the U.S.

The National Weather Service says about 150 million Americans are under a wind chill warning or advisory for dangerous cold and wind as an Arctic air mass spills south and eastward across the U.S.

Ted S. Warren / AP

Brutally cold temperatures and dangerous wind chills stayed put across much of the U.S. Monday, promising the coldest temperatures ever for Iowa’s presidential nominating contest, holding up travelers, and testing the mettle of NFL fans in Buffalo for a playoff game that was delayed a day by wind-whipped snow.

About 150 million Americans were under a wind chill warning or advisory for dangerous cold and wind, said Zack Taylor, a meteorologist with the National Weather Service in College Park, Maryland, as an Arctic air mass spilled south and eastward across the U.S.

Sunday morning saw temperatures as low as minus 20 degrees Fahrenheit (minus 6.7 degree Celsius) to minus 40 F in northern and northeast Montana. Saco, Montana, dropped to minus 51 F (minus 26 C). Subzero lows reached as far south as Kansas, Missouri, Illinois and parts of Indiana, Taylor said.



About 150,000 U.S. homes and businesses were without power Monday, the bulk of them in Oregon after widespread outages that started Saturday. Portland General Electric warned that strong winds forecast for Monday and threat of an ice storm Tuesday could delay restoration efforts.

The storm was blamed for at least four weekend deaths around Portland, including two people who died of suspected hypothermia. Another man was killed after a tree fell on his house and a woman died in a fire that spread from an open-flame stove after a tree fell onto an RV.

In Utah, where almost four feet (1.2 meters) of snow fell in the mountains over a 24-hour period, a snowmobiler was struck and killed Sunday night by a semitrailer about 70 miles (113 kilometers) southeast of Salt Lake City, according to the Utah Highway Patrol. The person killed was among four snowmobilers attempting to cross U.S. Highway 40 in the Strawberry Reservoir area.

In Wyoming, a backcountry skier was killed after triggering a 50-feet (15-meter) wide avalanche. The victim was swept into a gully and through brush and trees, then remained buried for about fifteen minutes before being found by a companion in the mountains south of Alpine, Wyoming, on Sunday afternoon, according to the Bridger-Teton Avalanche Center.

It marked the third U.S. avalanche fatality in recent days, following a Wednesday accident at a California ski resort that killed one person and injured three others, and another that killed a person on Thursday in the Idaho backcountry near the Montana border.

Swirling snow and avalanche dangers prompted road closures Monday across parts of Utah and Colorado. East of the resort community of Vail, Colorado, officials closed a 20-mile (32-kilometer) stretch of Interstate 70, the primary east-west highway through the state.

The Buffalo Bills renewed their call for shovelers at Highmark Stadium in Orchard Park, New York, on Monday morning to help dig out from more than a foot and a half of snow that fell through a blustery weekend that delivered the snow amid wind gusts of 60 mph (97 kph).

Crews had the turf cleared under a sunny sky by midmorning while citizen shovelers who took them up on the offer to earn $20 an hour worked in temperatures in the teens to clear seats for fans ahead of the 4:30 p.m. game.

At first glance it was a daunting task, Bob Isaacs of Buffalo acknowledged a few hours after arriving at 7:30 a.m. But he considered his work his contribution to the team.

“You got to remember you’re a Bills fan. It’s all part of the deal,” he said.

Neighboring towns saw even higher snow totals, thanks to roving Lake Erie-fed snow bands: 41 inches in Hamburg and Angola and three feet (about 1 meter) in West Seneca, Blasdell and South Buffalo.

Presidential campaigns, meanwhile, were expecting the cold and dangerous travel conditions to hamper turnout for the Iowa caucuses, which are the opening contest in the monthslong Republican presidential primary process. Voting is set to begin Monday night.

Monday also brought another day of delays for air travelers across the country. The flight tracking service FlightAware was reporting about 2,000 cancellations Monday within, into or out of the United States and thousands of delays.

Across the Deep South, freeze warnings were issued by the National Weather Service and covered large parts of Louisiana, Mississippi and Alabama.

In Mississippi, forecasters warned of a “long duration freeze” and said that temperatures in some locations would remain below freezing until Thursday. The lowest temperatures Tuesday night will be in the single digits above zero in the northern part of the state, according to the weather service’s Jackson office.

Highs weren’t expected to rise above 15 or 20 degrees F across Oklahoma, Arkansas, northern Texas and western Tennessee, the weather service’s Taylor said.

The winter storm was impacting travel across the central Appalachian region, with some areas of Middle Tennessee seeing as much as 8 inches of snow. Much of Kentucky and West Virginia were also blanketed, and the snow was expected to continue accumulating through early Tuesday. Meanwhile, wind chills in the Memphis area were predicted to reach as low as minus 5 degrees F (minus 21 C).

With the potential for record low temperatures in the single digits or teens in Texas, the state’s electrical grid operator, ERCOT, was asking consumers to conserve energy. About 26,000 customers were without power Monday.

Light snow was expected through the Mid-Atlantic and the Northeast through Monday and Tuesday, Taylor said, including 2 to 3 inches of snow forecasted for Washington, D.C. — what would be the most snowfall in a day in the nation’s capital in at least two years.