A deep freeze spread from the US midwest to the east and south, setting record low temperatures from Boston to Birmingham, and leaving 21 people dead.
The midwest and the east experienced temperatures colder than much of Antarctica.
All 50 states saw freezing temperatures at some point yesterday, including Hawaii, where it was -8C (18F) on top of Mauna Kea, a dormant volcano.
The big chill started in the midwest over the weekend, and by yesterday it covered about half of the country.
In New York City, the high was expected to be -12C (10F), and in Boston, around -8C (18F).
Across the south, records were shattered like icicles. Birmingham, Alabama, dipped to a low of -14C ( 7F), breaking the record of -11.7C (11F) set in 1970.
The deep freeze dragged on in the midwest as well, with the thermometer reaching -24C (-12F) overnight in the Chicago area.
More than 500 passengers were stranded overnight on three Chicago-bound trains that were stopped by blowing and drifting snow in Illinois. Food ran low, but the heat stayed on.
The cold turned deadly as authorities reported at least 21 cold-related deaths across the country since Sunday, including seven in Illinois, and six in Indiana.
At least five people died after collapsing while shovelling snow, while several victims were identified as homeless people who either refused shelter or did not make it to a warm haven soon enough to save themselves from the bitter temperatures.
The worst should be over in the next day or two. Warmer weather – at least, near or above freezing – is forecast for much of the stricken part of the country.
Yesterday many schools and day care centres across the eastern half of the US were closed so that youngsters would not be exposed to the dangerous cold.
Officials opened shelters for the homeless and anyone else who needed a warm place.
With the bitter cold slowing baggage handling and aircraft refuelling, airlines cancelled more than 2,000 flights in the US, bringing the four-day total to more than 11,000.
In New Orleans, which reported a low of -3C (26F), hardware stores ran out of pipe insulation. A pipe burst in an Atlanta suburb and a main road quickly froze over.
In Atlanta, a Ferris wheel near Centennial Olympic Park that opened over the summer to give riders a bird’s eye view of the city closed because it was too cold.
Farther south in Pensacola, Florida, a Gulf Coast city better known for its white sand beaches than frost, streets normally filled with joggers, bikers and people walking dogs were deserted early yesterday.
A sign on a bank flashed -7C (19F), and patches of ice sparkled in car parks where puddles froze overnight.
An estimated 190 million people in the US were subjected to the icy blast, caused by a kink in the “polar vortex,” the strong winds that surround the North Pole.