Polar vortex: Temperatures 'getting dramatically warmer' as cold spell eases

Polar vortex: Temperatures 'getting dramatically warmer' as cold spell eases

The worst of the brutally cold "polar vortex" that plunged millions of Americans into a deep freeze was over Wednesday, forecasters said, but temperatures remained between 10 and 20 degrees lower than normal.

The weather system was receding north, having set new record low temperatures in 50 cities on Tuesday.

Minneapolis-St. Paul, Minn., spent 62 consecutive hours below zero. Chicago spent 37 hours below that threshold, including 29 hours in double digits below zero, according to The Weather Channel.

Subzero temperatures were still widespread across the upper eastern half of the United States on Wednesday, but most areas affected by the extreme cold were beginning to thaw. Conditions are expected to be back to normal by Friday.

"It’s still going to be below average for most of the East but the worst of the Arctic outbreak is over with," said Guy Walton, a meteorologist at The Weather Channel.

"It will be getting dramatically warmer from today. It is still as much as 20 degrees below average in the Northeast but by Thursday temperatures will be almost back to normal."

he polar vortex is a cyclone of high winds which usually sits at the North Pole. Changes in the jet stream have meant these winds traveled south, encasing much of the U.S. and Canada in ice throughout the week.

At 4 a.m. ET Wednesday, Boston was at 8 degrees Fahrenheit, still well below its seasonal average of 23 degrees.

New York City was at 9 degrees with a wind chill of minus 8. "It’s certainly not nice but it is getting better," Walton said of the Big Apple.

Washington, D.C., was at 14 degrees, and Atlanta was at 18 degrees with a wind chill of 8 degrees.

Parts of Minnesota and North Dakota -- where the cold system was at its most brutal through the week -- were at minus 16 degrees Fahrenheit. Michigan, Illinois, and Indiana were seeing temperatures of minus 4 to minus 8 degrees.

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