(NewsNation) — A dangerous arctic blast will continue sweeping across the U.S. on Monday and linger through at least midweek, prolonging a bitter cold that set record-low temperatures in parts of the country and threatens to further disrupt daily life, including air travel and the Iowa caucuses.

The National Weather Service said wind chills are expected to push temperatures 30 degrees below zero from the Northern Rockies to northern Kansas and into Iowa, testing the hardiness of caucusgoers willing to brave the deep chill on Monday.

NewsNation Meteorologist Max Tsaparis forecasts the dangerous wind chills will last through this week and may relinquish its hold by Thursday.

More than 500 domestic flights at U.S. airports have been canceled so far on Monday – with thousands more shelved into the past two days – as major winter storms impact air travel.

Flight-tracking data by FlightAware suggests that, as of 6:30 a.m. ET on Monday, 561 flights within, into or out of the U.S. have been canceled, and 1,484 flights were delayed.

On Sunday, 7,971 flights were canceled and 1,567 delayed. More than half of flights into and out of Buffalo Niagara International Airport were canceled. Scores of flights were also canceled or delayed at Chicago, Denver and Seattle-Tacoma airports.

Arctic storms left at least four dead and knocked out electricity to tens of thousands in the Northwest, brought snow to the South and walloped the Northeast with blizzard conditions forcing the postponement of the Pittsburgh Steelers vs. Buffalo Bills NFL playoff game hosted in bone-chilling Buffalo, New York.

The game is now scheduled for Monday afternoon. The weather service expects heavy lake-effect snow to push into upstate New York from Lake Erie, adding to the 1 to 2 feet of snow already blanketing the region. Snow fell at a rate of 2 inches per hour.

Sub-zero wind chills will grip much of the country, plunging to 50 degrees below zero in Montana and the Dakotas.

Other parts of the country could see temperatures drop 25 to 40 degrees below normal, from the Rockies to the Ohio Valley.

As temperatures in Texas plunged, the state’s power grid operator appealed to residents to voluntarily conserve electricity Monday morning due to the cold weather causing “record breaking demand” for energy. A deadly freeze in 2021 left millions of Texans without power but state officials this week expressed confidence about the grid’s reliability as the cold front approached.

Freezing rain is expected to pelt parts of the Southern Plains and Southern Appalachians.

In Oregon, more than 120,000 homes and businesses were without electricity, most of them in the Portland metro area, a day after high winds and a mix of snow and ice brought down trees and power lines.

Some 100 trees toppled over the weekend in a community just south of Portland, including one that fell on a house and killed a man. Two other people died of suspected hypothermia and a fourth died in a fire that spread from an open-flame stove after a tree fell onto an RV.

Widespread power outages affecting tens of thousands were also reported Sunday in Michigan, New York, Pennsylvania and Wisconsin. In Nebraska, the Omaha Public Power District asked customers to conserve electricity to prevent outages.

The Associated Press contributed to this report.