As of midnight CST Tuesday, 73% of the lower 48 states were covered in snow, the highest percentage in the NWS's database, which dates back to 2003.
According to the NWS analysis, the only three states without snow cover were Florida, Georgia and South Carolina.
For comparison, only 31% of the country, on average, was covered in snow throughout February.
Satellite imagery from Thursday shows clouds stretch from Texas, up through New England and across the Plains to the Pacific northwest.
Winter storms and record-low temperatures wreaked havoc on Texas this week, leaving homes without heat, electricity and safe drinking water.
Meanwhile, the Appalachians, northern Maryland and southern Pennsylvania braced for heavy snow and ice. Snow fell in Connecticut, New Jersey and New York.
Little Rock, Arkansas, got 15 inches of snow in back-to-back storms, tying a 1918 record, the National Weather Service said.
Weather-related outages also struck Oregon, where some customers have been without power for almost a week.
Yet after the historic blast of arctic air, weather models are hinting at a dramatic shift to warmer temperatures for millions of people over the next 7 to 10 days, according to forecasters.
The Associated Press and CNN contributed to this report.