An icy blast descending across the US has seen record-breaking low temperatures, with a “polar vortex” leading to the worst freeze in decades and wind chills of -55 Celsius.
It is the coldest period for 20 years in the capital Washington DC, and is forecast to continue with the mercury dipping well below zero right across the country.
The worst of the heavy snow is believed to be over, but forecasters say the chill is set to stay at least into early next week, stemming from a pool of cold, dense air sweeping down from the North Pole and Canada.
“If you're under 40 you've not seen this stuff before,” said Weather Bell meteorologist Ryan Maue.
At least 16 people have died as a direct result of the snow storm which affected areas from the Midwest to the eastern seaboard, including three who officials say were killed simply by the extreme cold.
Yesterday saw temperatures of -38C recorded in Maine – in such conditions, experts said, it takes just minutes for exposed skin to get frostbitten and hypothermia can quickly follow.
Looking forward, the forecasts are for -31C in North Dakota, -35C in Minnesota and -26C in Indianapolis and Chicago.
Even in Kentucky, a southern state where average temperatures rarely get below zero, the forecast tomorrow is for -18C, described as “definitely record-breaking” by weather service meteorologist Christine Wielgos.
“It's just a large area of very cold air that comes down, forms over the North Pole or polar regions ... usually stays in Canada, but this time it's going to come all the way into the eastern US,” said fellow meteorologist Phillip Schumacher.
With wind chills reaching -45, -50 or even -55C, transport, schools and sports fixtures have all been affected.
State officials have shut down schools for the entire of Minnesota tomorrow – the first blanket decision of its kind for 17 years.
The cold temperatures kept last week’s snow light and powdery, preventing it from weighing down electrical lines or tree limbs. As a result there were only a few thousand power cuts in the Northeast.
However, a transformer malfunctioned after an overnight blizzard in Canada, knocking out power to 190,000 customers in Newfoundland. About 125,000 people remained without electricity yesterday.
Additional reporting by AP