Arctic chill freezes large areas of US and Canada

A brutal chill held much of the United States and Canada in its grip, with a record-breaking cold snap bringing temperatures lower than on the surface of Mars.

Schools, businesses and government offices were closed on Tuesday. Water mains and household pipes froze. Planes were grounded, trains were halted and roads and sidewalks became ice rinks.

A skier slides across Lake Calhoun in Minneapolis on Tuesday after Arctic air swept much of the United States and Canada, shattering decades-old temperature records and snarling air, road and rail travel. Eric Miller / Reuters

It was so cold in Chicago that the polar bear at the Lincoln Park zoo, who admittedly had not built up the winter fat stores of her wild cousins, was brought inside to warm up.

In Kentucky, an escaped inmate begged to be let back into prison so that he could warm up after spending the night shivering in an abandoned house.

All of Canada and every state in the US apart from tropical Hawaii recorded temperatures below freezing on Tuesday - even usually sunny and warm Florida and California.

But the most dangerous cold - that which can cause frostbite in a minute and death in a matter of hours - hit the Midwest as the "polar vortex" brought frigid air from the Arctic.

The town of Embarrass in Minnesota recorded the lowest temperature in the United States of -37 C.

Then there was the wind chill, a calculation that represents how much colder it feels when the blinding gusts hit you in the face.

That dipped as low as -52 C in Montana and was between -40 C and -50 C in parts of Illinois, Indiana, Iowa, Maryland, Michigan, Minnesota, Nebraska, North Dakota, Ohio, Pennsylvania, South Dakota, Virginia, West Virginia and Wisconsin.

That's cold enough to toss a cup of boiling water into the air and watch it turn into snow before it hits the ground.

The Mars Rover has been sending back daily temperature readings from its tour of the Red Planet ranging from -25 to -31 C.

"To be fair, though, Mars is still way colder," the Smithsonian Institute wrote in a blog post. "The Curiosity rover is driving around in a crater at, roughly, the equivalent latitude of Venezuela."

But then again, Mars is 125 million km farther away from the Sun.

For a more Earthly comparison, the Amundsen-Scott South Pole Station recorded a temperature of -23 C and a wind chill factor of -35 C on Tuesday.

The brutal chill came as people in the Great Lakes region were still digging out from two huge snow storms.

More than 500 people spent Monday night stuck on a train stranded by snowdrifts on the line between Detroit and Chicago.

Commuter lines and even Chicago's elevated trains were also put out of service by the snow, while frigid temperatures froze switches and signals.

Nearly 2,500 flights were canceled in the US on Tuesday and 3,400 delayed, bringing the number of flights canceled since the latest snowstorm hit on Thursday to more than 18,000.

Toronto's Pearson Airport halted ground operations temporarily because of frozen equipment and concerns over the safety of airport personnel, it said on its Twitter account.

The governor of Illinois declared a state of emergency on Monday and called up the National Guard to help rescue stranded motorists as high winds whipped up blinding snow.

Guardsmen were also deployed in Indiana and New York, a Pentagon spokesman said.

Even hardy Canadians were complaining of the cold amid widespread power cuts.

Temperatures as low as -50 C with wind chill plunged the western Prairies region into a deep freeze.

The streets of Toronto, Montreal and the capital Ottawa were coated with black ice after unusually warm temperatures brought rain on Monday before the mercury plunged again.

The cold snap eased its grip on much of the US on Wednesday, with winds calming and the weather warming slightly.

Agence France-Presse