More than 100 million Americans have been warned to brace for a “bomb cyclone” bringing severe winter weather to the US.

Temperatures across central states have plunged, with the mercury dipping to -25F (-31C) in Montana.

Places like Des Moines, Iowa, will feel like -37F (-39C) making it possible to suffer frostbite in less than five minutes.

More than 2,200 flights in and out of US airports have been cancelled and 114 million people are under weather alerts as heavy snow and life-threatening wind chills sparks holiday travel chaos.

Just a few days before Christmas, nearly 7,000 flights within, to, or out of the US have been delayed with blizzard warnings in effect for portions of eight states.

Many of the cancelations and delays are happening at some of the country’s busiest airports.

Chicago O’Hare International Airport has reported at least 550 cancellations and more than 500 delays while Chicago Midway International Airport has had more than 250 cancellations and 73 delays.

Denver International Airport has recorded 565 cancellations and nearly 580 delays as of Thursday afternoon local time.

More than 120 million people are under wind chill alerts. 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.”