A massive winter storm has gripped 200 million Americans and has been linked to at least 12 deaths ahead of the holiday weekend.
On Friday, more than 1.5 million people lost power, and thousands of flights were cancelled.
The massive storm stretches over 2,000 miles (3,200 kilometres) from Texas to Quebec.
Blizzard conditions have been brought to the Great Lakes on the US-Canada border by a bomb cyclone, which occurs when atmospheric pressure drops.
In Canada, Ontario and Quebec bore the brunt of the Arctic blast, with hundreds of thousands without power.
From British Columbia to Newfoundland, much of the rest of the country was under extreme cold and winter storm warnings.
They fled south to avoid the winter. They were still discovered by the storm.
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The US National Weather Service (NWS) said its Friday map “depicts one of the greatest extents of winter weather warnings and advisories ever”.
Temperatures in Elk Park, Montana, fell to -50F (-45C), while Hell, Michigan, froze over.
On Friday night, the temperature in the snow-covered community was 1F (-17C). “It’s pretty cold here, but we’re having a hell of a time,” Emily, a bartender at Smitty’s Hell Saloon, told the BBC.
According to tribal officials, snowed-in Native Americans in South Dakota burned clothes for warmth after running out of fuel.
Snowfall was expected to be heavy in parts of Pennsylvania and Michigan. Buffalo, New York, was expecting at least 35 inches of rain (89cm). The NWS reported that more than eight million people were still under blizzard warnings.
Flooding has occurred along the coasts of New England, New York, and New Jersey.
Some residents in the Pacific Northwest ice-skated on frozen streets in Seattle and Portland.
Even the traditionally milder southern states of Louisiana, Alabama, Florida, and Georgia were under hard-freeze warnings.
Photographs of a winter storm in the United States
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A number of storm-related fatalities have occurred as a result of traffic accidents, including a 50-car pile-up in Ohio that killed two motorists.
A shortage of snow plough operators was exacerbating travel problems across the country, with low pay rates being blamed.
According to the flight tracking website FlightAware, over 5,600 US flights were cancelled on Friday as passengers tried to get home for Christmas.
According to PowerOutage.us, one million customers in the United States were without power as of Friday night.
To save energy, utilities across the Tennessee Valley implemented rolling blackouts.
More than 100 daily cold temperature records could be tied or broken over the next few days, according to the NWS. Records dating back decades have already been broken:
Denver, Colorado, reached -24F on Thursday, the coldest temperature since the 1990s. Craig McBrierty, 34, from Scotland who now lives in Denver, told the BBC that it is “colder than I have ever experienced.”
Wichita, Kansas, experienced its coldest wind chill (-32 degrees Fahrenheit) since 2000.
For the first time in 26 years, temperatures in Nashville, Tennessee, fell below zero.
On Tuesday, Casper, Wyoming, set a new low of -42F.