Tens of millions of Americans endured bone-chilling temperatures, blizzard conditions, power outages and cancelled Christmas plans as an extreme winter storm gripped much of the country. 

More than 200 million people – about 60% of the US population – were under some form of winter weather advisory or warning on Friday, the National Weather Service said, calling it a “historic winter storm”.

Temperatures across central states have plunged, with the mercury dipping to -50F (-45.6C) in Montana.

Places like Des Moines, Iowa, will feel like -37F (-38C) making it possible to suffer frostbite in less than five minutes, according to the National Weather Service.

More than 1.4 million homes and businesses were without power on Friday morning and holiday travel plans were upended as more than 3,100 flights in and out of US airports were cancelled on the day before Christmas Eve.

Fatalities have already begun to be reported with three deaths so far recorded on roads in Kentucky according to the state’s Governor.

The storm has now intensified into a bomb cyclone according to the National Weather Service, which says the atmospheric pressure of the storm has dropped rapidly enough over the past 24 hours to classify the system that way.

The huge storm stretched from border to border. In Canada, British Columbia reached a low of -62.7F (-52.6C). And in Mexico, migrants waited near the US border in unusually cold temperatures for a court decision on lifting asylum restrictions.

Florida residents have been warned to look out for iguanas falling from trees as sub-zero temperatures can immobilise the cold-blooded creatures, causing them to lose their grip and fall to the ground.

More than 181 million people are under wind chill alerts and 11 million are affected by blizzard warnings. Forecasters said temperatures in some areas have dropped more than 30 degrees in a matter of minutes.

By the time the weather system has moved through, an estimated 192 million people across 46 states will have experienced wind chills below zero.

Hundreds of drivers stranded

In South Dakota, more than 100 drivers became stranded when the arctic blast hit the state with sub-zero temperatures.

As authorities worked to rescue those stranded, the local sheriff’s office told drivers to stay in their vehicles and call 911.

Rosebud Sioux Tribe emergency manager Robert Oliver said tribal authorities have been working to clear roads to deliver propane and firewood to homes, but face a relentless wind that has created drifts over 10 feet in some places. He said five have died in recent storms, including a blizzard from last week.

In Minnesota, police responded to nearly 50 vehicle crashes between Wednesday night and Thursday morning.

Wet roadways also caused 118 vehicle spinouts and a crash involving a semi-truck, the State Patrol said.

In South Dakota, the winter storm system left some motorists stranded on city streets, according to the Pennington County Sheriff’s Office. Workers removed people from their cars throughout the night. A photo from the agency showed people sleeping on makeshift beds on the floor of a building.

‘This is not like a snow day when you were a kid’

President Joe Biden has warned Americans to take the storm seriously.

“This is not like a snow day when you were a kid,” he said after a briefing from federal officials.

“This is serious stuff.”

High demand at homeless shelters

In Portland, Oregon, officials opened four emergency shelters. In the city’s downtown, Steven Venus tried to get on a light-rail train to get out of the cold after huddling on the sidewalk overnight in below-zero temperatures.

“My toes were freezing off,” he said, a sleeping bag wrapped around his head, as he paused near a flimsy tent where another homeless person was taking shelter.

Courtney Dodds, a spokeswoman for the Union Gospel Mission, said teams from her organisation had been going out to try to persuade people to seek shelter.

“It can be really easy for people to doze off and fall asleep and wind up losing their lives because of the cold weather,” she said.