A blast of Arctic air has gripped the US midwest with the coldest temperatures in two decades causing at least four deaths.
The biting cold temperatures and heavy snow has also forced businesses and schools to close and led to the cancellation of thousands of flights.
Shelters for the homeless are overflowing due to the severe cold described by some meteorologists as the “polar vortex”.
Temperatures were 20 to 40 degrees below average in parts of Montana, North and South Dakota, Minnesota, Iowa, Wisconsin, Michigan and Nebraska, according to the National Weather Service.
Babbitt in Minnesota was the coldest place in the US yesterday at -37F (-38.3C), according to the National Weather Service.
It was chillier than Mars in recent days, where NASA’s rover Curiosity showed a high temperature on 2 January of -32.8F (-36C).
More than half the flights at Chicago’s O’Hare International Airport were cancelled as fuel supplies froze, leaving crews unable to fill aircraft tanks.
The afternoon temperature in Chicago was -12F (-24C).
The polar vortex, the coldest air in the northern hemisphere that hovers over the polar region in winter, but can be pushed south, is moving towards the US east coast where temperatures are expected to drop later today.
The cold air mass originated over Siberia, the National Weather Service said on its website.
The coldest temperatures in years and gusty winds are expected as far south as Brownsville in Texas and central Florida, the National Weather Service said.
New York Governor Andrew Cuomo declared a state of emergency, announcing that parts of the New York State Thruway in Western New York would be closed due to extreme winter weather conditions there.
At least four weather-related deaths were reported, including a 48-year-old Chicago man who had a heart attack while shovelling snow on Sunday and an elderly woman who was found outside her Indianapolis home early on Monday.