A deadly arctic deep freeze enveloped the Midwest with record-breaking temperatures on Wednesday, triggering widespread closures of schools and businesses, and prompting the US Postal Service to take the rare step of suspending mail delivery to a wide swath of the region.
The painfully cold weather system holding much of the Midwest in a historic deep freeze sent temperatures plunging to a record low in northern IL on Thursday, but a dramatic swing of as much as 80 degrees is expected by early next week.
Chicago recorded a low temperature of about minus 23 degrees Fahrenheit (minus 30 Celsius) - not a record, but close to it. Minneapolis recorded minus 27 F (minus 32 C). The community outside of Ann Arbor was expected to see temperatures drop to minus-26 overnight into Thursday.
A forecast for warmer weather by the weekend offered little comfort to those enduring icy conditions, brutal winds and temperatures as low as minus 30 degrees.
You know it's cold when people go outside to do experiments with water..
States of emergency have been declared from Wisconsin and MI, down to Alabama and Mississippi. "They are life-threatening temperatures, and they should be treated accordingly", he cautioned.
The National Weather Service is warning people in the IL city to cover their mouths and "to protect your lungs from severely cold air, avoid taking deep breaths; minimize talking".
As of Wednesday morning, Chicago was already significantly colder than Antarctica, with the city at -21F and the south pole at -11F.
Homeless shelters were filled to more than capacity in Omaha, Nebraska. They also were filling up in Detroit. Heavy lake effect snow has been hitting states downwind of the Great Lakes; the NWS says that snow will finally start to taper off by Thursday night and into Friday.
The cold has caused at least 12 deaths since Saturday across the Midwest, according to officials and news media reports.
Heavy snow was forecast in the northern stretches of ME and snow squalls predicted for other parts of the east coast.
In Washington, where the low hit 10F (-12C) and was expected to peak at only 24F (-4C), a small crowd of tourists braved the cold to take pictures outside the White House.
"That wind chill out there is not even a joke", he said. "I can feel my skin tighten up".
This week's cold weather will be just a memory within a few days.
In Chicago, residents were bracing for another snowstorm, and Mayor Rahm Emanuel urged people to stay indoors.
Many cities in the Midwest have opened warming shelters for the tens of millions of people who will be affected.
In Fargo, North Dakota, where the temperature dropped to minus 24F (minus 31C), Dan Hallock, an advertising executive, marveled that people were still working outside as he bought coffee.
American Indian tribes in the Upper Midwest were doing what they could to help members in need with heating supplies.
America's northern neighbor Canada was also contending with extreme cold, with frozen water pipes, snarled travel on a major waterway, and temperatures as low as -40F (-40C) on Wednesday. A blast of warm air from misplaced heat in Morocco last month made the normally super chilly air temperatures above the North Pole rapidly increase.