Ice storms, heavy snow and freezing rain knocked out power, closed roads and saw 1,000 cancelled flights in southern Texas.
Bad winter weather is extremely rare as far south as the Gulf Coast. President Joe Biden has declared a federal emergency.
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Multi-vehicle crash in Oklahoma winter weather
The ice storms knocked out nearly half the wind-power generating capacity of Texas as the rare deep freeze across the state brought turbine towers to a halt.
Rolling power outages were also brought in by the Electric Reliability Council of Texas (ERCOT) on Monday, meaning thousands went without electricity for short periods, as temperatures fell as low as -5C around Houston and Dallas.
Average central and southern Texas temperatures in February usually hover between 20- 24C.
An Arctic air mass causing the chill gripped much of the country, from the Pacific Northwest through to the Great Plains and into the mid-Atlantic states.
Winter storm warnings were posted for much of the Gulf Coast region, Oklahoma and Missouri, the National Weather Service said.
Two people play in the snow in San Antonio, Texas
Forecasts predict more heavy snow and freezing rain to spread across a larger swathe of central and eastern sections of the country on Monday, with a storm front in the west likely to dump up to 60cm of snow in the northern Rockies.
Marc Chenard, a meteorologist with the National Weather Service’s Weather Prediction Center, said: “Typically, we just don’t have quite this much cold air in place that far south.”
Nearly 120 crashes, including a 10-car pileup had been reported across the region.
The storm has prompted officials in Houston to advise residents to prepare for power outages and hazardous roads – similar to those experienced in the wake of a category five hurricane.
A snowman in the shadow of a palm tree in El Paso, Texas Photo: Brigadier Andy Cox, British Army
Texas Governor Greg Abbott has issued a disaster declaration for all of the state’s 254 counties, describing the conditions as “extremely dangerous”.
A presidential emergency declaration allows the US Department of Homeland Security and the Federal Emergency Management Agency to co-ordinate disaster relief efforts and provide assistance, equipment and resources to those affected by the storm.
More than 760 flights were cancelled at Texas’ main airport, Dallas-Fort Worth, and 200 more at regional hubs.
Into Tuesday, 20 to 30 centimetres of snow is expected in central Oklahoma, and in Memphis, Tennessee, main roads were still impassable and queues were forming at supermarkets as people rushed to stock up.
The bad conditions have reached Mississippi, Kentucky and West Virginia too.
Earlier this month heavy snow disrupted the COVID-19 vaccine rollout in New York.