CNN  — 

The prolonged winter storm that brought heavy snow, high winds and brutal cold to most of the US this past week has killed at least 37 people and had hundreds of thousands without power on Christmas morning.

Perhaps the worst impact was around Buffalo, New York, where 43 inches of snow fell as of Sunday morning, according to the National Weather Service. The snowfall and blizzard conditions made roads impassable, froze power substations and left more than a dozen people dead, Erie County officials said.

The conditions eased slightly on Sunday, allowing emergency responders to get out and see the extent of the problem.

“I don’t want to say that this is going to be it because that would be a fallacy for me to say that, because we know that there are people who have been stuck in cars for more than two days,” Erie County Executive Mark Poloncarz said Sunday. “There are people in homes who are below freezing temperatures.”

New York Gov. Kathy Hochul called it the “most devastating storm in Buffalo’s long storied history” due to its power and its extended length.

“It’s a crisis of epic proportion,” Hochul told CNN’s Paula Reid on Sunday.

Over the past week, this winter storm brought dangerously cold temperatures, blizzard conditions and coastal flooding to almost the entirety of the US, wrecking Christmas plans along the way.

More than 55 million people were under wind chill alerts Sunday morning, and freeze warnings are in effect across the South.

The blizzard conditions persisted Sunday across the Great Lakes, while frigid cold temperatures gripped the eastern two-thirds of the country.

Some major cities in the Southeast, Midwest and East Coast recorded their coldest Christmas in decades. In Florida, it will be the coldest December 25 since 1983 for Miami, Tampa, Orlando and West Palm Beach.

New York City also saw record cold temperatures on Christmas Eve at several locations, including its JFK and LaGuardia airports. The high at Central Park was 15 degrees, marking it the second-coldest December 24 in at least 150 years, according to the National Weather Service.

Temperatures are forecast to rebound later in the week with a much-welcomed warming trend with above-normal temperatures.

About 250,000 homes and businesses in the US had no electricity service as of about 11 a.m. ET Sunday, with nearly half of those affected in Maine and New York, according to PowerOutage.us. Since the start of the storm the number of outages has at times exceeded a million customers.

In pictures: Winter storm impacts the US

A power grid operator for at least 13 states in the country’s eastern half asked customers to conserve power and set thermostats lower than usual from early Saturday to 10 a.m. on Sunday because usage was straining capacity.

The operator, PJM Interconnection, serves about 65 million people in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia. The operator warned rolling blackouts could happen if the strain becomes too much.

In New York, utility companies Con Edison and Natural Grid US also urged customers to conserve energy, citing extreme weather conditions and increased energy demand on interstate pipelines carrying natural gas into the city.

Meanwhile, a shortage of electricity in Texas prompted the US Department of Energy to declare an emergency Friday, allowing the state’s energy provider to exceed environmental emissions standards until energy usage drops.

In Jackson, Mississippi, frigid temperatures are hampering efforts to repair a large water main break late Saturday, which has caused a loss in water pressure for residents, city officials said.

“We are grateful to the crews who are braving these frigid temperatures on this Christmas Eve night, while working to restore pressure to residents. Their sacrifice does not go unnoticed and is appreciated not only by this administration, but also by every resident who is affected,” the release stated.

The brutal weather conditions have also snarled travel during the busy holiday weekend, with more than 5,000 flights canceled Friday, more than 3,400 flights canceled Saturday, and more than 2,800 canceled for Christmas Day.

Out of the 17 weather-related fatalities recorded across New York, 16 were in Erie County, officials said, and one was a fatal carbon monoxide poisoning reported in Niagara County, according to the Niagara County Sheriff’s Office.

Blistering blizzard conditions swept the region, and Poloncarz, the county executive, said about 500 motorists found themselves stranded in their vehicles Friday night into Saturday morning, despite a county driving ban put in place during the storm.

National Guard troops had been called in to help “rescue people that are stuck in vehicles,” he said.

Of the deaths reported early Sunday – with individuals ranging in age from 26 to 93 years of age – “some were found in cars and some were found actually on the street in snow banks,” Poloncarz said.

Two died in separate incidents Friday night when emergency medical personnel could not get to their homes in time for medical emergencies, Poloncarz said Saturday morning. Details about a third death, confirmed by a county spokesperson Saturday afternoon, weren’t immediately available.

“The loss of two lives in Buffalo – storm related – because people were not able to get to medical attention, is again a crisis situation that unfolds before your eyes and you realize that lifesaving ambulances and emergency medical personnel cannot get to people during a blizzard situation,” New York Gov. Kathy Hochul said Saturday.

Hochul said she will ask the federal government “for a declaration of emergency that’ll allow us to seek reimbursements for the extraordinary expenses of all the overtime and the fact that we brought in mutual aid from other parts of the state.”

Other storm-related deaths have been reported in the country. They include:

• Colorado: Police in Colorado Springs, Colorado, reported two deaths related to the cold since Thursday, with one man found near a power transformer of a building possibly looking for warmth, and another in a camp in an alleyway.

• Kansas: Three people have died in weather-related traffic accidents, the Kansas Highway Patrol said Friday.

• Kentucky: Three people have died in the state, officials have said, including one involving a vehicle crash in Montgomery County.

• Missouri: One person died after a caravan slid off an icy road and into a frozen creek, Kansas City police said.

• Ohio: Nine people have died as a result of weather-related auto crashes, including four in a Saturday morning crash on Interstate 75, when a semi tractor-trailer crossed the median and collided with an SUV and a pickup, authorities said.

• Tennessee: The Tennessee Department of Health on Friday confirmed one storm-related fatality.

• Wisconsin: Wisconsin State Patrol on Thursday reported one fatal crash due to winter weather.

Strong winds behind the arctic cold front that pushed through this week will lead to lake-effect snow and blizzard conditions at times across portions of the Great Lakes on Sunday.

Blizzard warnings, winter storm warnings and winter weather advisories blanket much of the Upper Midwest, Great Lakes region and Ohio Valley.

An additional 8 to 16 inches of lake-effect snow is possible.

The storm system is forecast to gradually weaken as it lifts into southeastern Canada, moving slowly during the next couple of days and pulling arctic air from Canada down into much of the eastern side of the country.

The Arctic blast will slowly moderate into Monday.

The cold temperatures combined with dangerous wind chills will create a potentially life-threatening hazard for travelers who become stranded, people who work outside, livestock and pets, according to the National Weather Service.

“In some areas, being outdoors could lead to frostbite in minutes,” the Weather Service warned.

As the frigid air continues to blast the warm waters of the Great Lakes, lake-effect snows and blizzard conditions are expected to continue, but slowly become less intense.

Still, strong gusty winds initially up to 60 mph accompanying the snow downwind from the Great Lakes will continue to make for extremely dangerous conditions on the road.

By Christmas night into Monday, another low pressure system coming from the Pacific will deliver the next surge of moisture toward the Pacific Northwest and then into northern California, according to the Weather Service.