It's a battle of the seasons from coast to coast as warm air moves into the eastern half of the country while the West is dealing with cold temperatures that haven't been felt in years.
As a result, more than 60 temperature records, including both highs and lows, could be broken across the United States on Wednesday.
Cold air is pushing into the western U.S., and record-low temperatures could be broken from the Pacific Northwest and California into the Northern Plains and southward to the Oklahoma and Texas panhandles.
In the East, temperatures will be warm for one more day before a winter storm is expected to move into the Northeast, bringing the possibility of more than a foot of snow to some areas.
Record-high temperatures could be broken up and down the East Coast on Wednesday from Florida to the mid-Atlantic, the Northeast and New England.
It's bitterly cold in parts of the western U.S., and dozens of records could be broken.
Wednesday's record-low temperature in Seattle is 24 degrees set back in 1945, and that could be challenged Wednesday morning.
To the south in Portland, Oregon, its record low of 24 degrees was set in 2018, and that, too, could fall Wednesday morning.
The cold air will stretch southward into California on Thursday morning, and records could be broken across the Golden State.
Eureka, California, is forecast to drop to 28 degrees Thursday morning, which would break its old record of 31 degrees set in 2013.
Sacramento, California, is expected to dip to 27 degrees, which would break its old record of 29 degrees.
Even Southern California is getting in on the action Thursday morning.
San Diego will be close to breaking its record of 38. It's forecast to drop to 39 degrees Thursday morning.
Shifting to the eastern half of the United States, records could be broken along the East Coast from Maine to Florida.
Bangor, Maine, could hit 60 degrees Wednesday afternoon, breaking its old record of 57 degrees set in 1984.
Elsewhere in New England, records could be broken in Boston, Providence, Rhode Island, and Bridgeport, Connecticut.
New York City could also break its old record.
The old record at John F. Kennedy Airport in Queens is 62 degrees set in 1990. It's expected to be around 65 degrees on Wednesday.
Heading south along the East Coast, more records could be broken from the mid-Atlantic to Florida and along the Gulf Coast.
Wilmington, North Carolina, has a record high of 80 degrees set in 1975. The area is forecast to get to around 79 degrees, putting that record in jeopardy.
Tallahassee, Florida, could also tie or break its old record of 83 degrees set in 2019.
The warm weather will stick around in the Southeast on Thursday, but cold air will be filling in across the Northeast and New England in advance of a winter storm.
Temperatures could tie or break records from North Carolina southward into Georgia and Florida.
Lakeland, Florida, could tie its record of 88 degrees set in 2019.
The record could also be tied or broken in Albany, Georgia, as it's forecast to get to around 86 degrees on Thursday.