Road and utility crews faced the task on Monday of digging out and restoring some normalcy around Buffalo, New York, where a blizzard considered the area's worst in 45 years buried snow plows, stranded motorists in cars and killed at least 13 people.

The lethal blizzard took form late on Friday and pummeled western New York through the Christmas holiday weekend, capping an Arctic freeze and winter storm front that had extended over most of the United States for days, as far south as the Mexican border.

The scope of the winter storm has been unprecedented, stretching from Canada as far south as the Rio Grande.

Forecasters say the storm will ease off in the next few days but the advice remains to avoid travelling unless essential.

The storm has wreaked havoc for days but power has been steadily restored after earlier blackouts.

Fewer than 200,000 customers were without power as of Sunday afternoon EDT, down from a peak of 1.7 million, the Associated Press reports.

Thousands of flights have been cancelled, preventing many people from reaching their families at Christmas.

More than 55 million Americans remained under wind chill alerts on Sunday.

The "bomb cyclone" winter storm - which occurs when atmospheric pressure plummets, causing heavy snow and winds - has disrupted travel across the US.

New York State Governor Kathy Hochul - a native of Buffalo - said : "This will go down in history as Buffalo's most devastating storm."

"It is [like] going to a war zone and the vehicles along the sides of the roads are shocking," she told reporters on Sunday evening.

Residents still faced a "very dangerous life-threatening situation" and anyone in the area should remain indoors, she said.

Twelve deaths were confirmed in Erie County, with some victims found dead in cars or snow banks.