Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Frigid Arctic Air, Winter Storms Grip Much of US AFP HOUSTON - Much of the United States was in the icy grip of an "unprecedented" winter storm on Monday as frigid Arctic air sent temperatures plunging, forcing hundreds of flight cancellations, making driving hazardous and leaving millions without power in Texas. Texas Governor Greg Abbott issued a disaster declaration for the southern state, and the National Weather Service (NWS) said more than 150 million Americans were under winter weather advisories. "I urge all Texans to remain vigilant against the extremely harsh weather," Abbott said in a statement. The NWS described conditions as an "unprecedented and expansive area of hazardous winter weather" from coast-to-coast. More than 2.7 million people were without power in Texas, according to PowerOutage.us, and temperatures in the major metropolis of Houston dipped to 16 degrees Fahrenheit (minus nine Celsius). President Joe Biden issued an emergency declaration for Texas on Sunday providing federal assistance to supplement state relief efforts. Texas is not used to such brutal winter weather and the storm caused havoc in parts of the state, including a 100-car pileup on Interstate 35 near Fort Worth last week that left at least six people dead. Austin-Bergstrom International Airport said that all flights had been canceled on Monday due to the "historic weather" and Houston's George Bush Intercontinental Airport also shut down. The NWS said Arctic air was driving a "polar plunge" that is expected to bring record-low temperatures. Much of the United States has been shivering under chilly temperatures for days, with about half of all Americans now under some sort of winter weather warning. Temperatures have dropped across the country, with only parts of the southeast and southwest dodging it. The cold snap has led to heavy snowfalls and ice storms that have caused a spike in electricity demand and power outages. .