The temperature ups and downs are downright extreme in parts of Texas. In less than 24 hours, Dallas went from a high of 81 degrees Fahrenheit at Love Field to a low of 17 degrees Monday morning, CNN meteorologist Sean Morris reported.

What's responsible for the sudden drop? A cold mass from Canada brought frigid air moving southeast across Texas, CNN meteorologist Todd Borek reported.

Across the Southern Plains, temperatures Monday afternoon were 30 to 40 degrees below normal, Morris said.

Winter storm moves east

Sorry, fans of springtime: Temperatures are expected to remain below normal this week. Several more pushes of cold, arctic air will invade the United States east of the Rocky Mountains, Morris said.

As of now, it seems the snowstorms won't be record-setting, but several weak systems will cause some travel headaches, Morris said.

Washington, Baltimore and Philadelphia all got hit by snow Monday, and the Midwest and Great Plains were put into the freezer.

More than 2,950 U.S. flights had been canceled by Monday night, according to FlightAware.com, a flight tracking service. Ronald Reagan Washington National Airport had canceled about 80% of its departing flights by Monday afternoon, and Philadelphia International Airport had nixed about a third of its schedule.

(Source: CNN)