Santa will most likely be wiping sweat from his brow as he makes his trek across the U.S. this year, as Christmas Day could end up being the warmest on record for millions.
But the record warmth isn't waiting until Christmas. That present has long been opened. On Monday, all-time December heat records were tied or set inLubbock, Texas(85 degrees);North Platte, Nebraska(78 degrees); andTucson, Arizona(85 degrees). Over 100 stations have broken their record highs as of Tuesday, with Tuesday daily records being tied or broken in cities like Dallas (82 degrees), Shreveport (83 degrees), Houston (81 degrees) and Sprinfield, MO (73 degrees).
Christmas high temperatures are expected to run more than 20 degrees above average across much of the South and Plains, with highs soaring into the 60s, 70s and 80s for that large swath of the nation.
Here's a look at who could face a record-warm Christmas this year:
Cities such as Atlanta, Oklahoma City, Kansas City, Amarillo, Denver and Albuquerque could tie or break their warmest Christmas on record — not entirely surprising given their location in the southern and central U.S., where the temperatures are warmest.
Some of the more surprising warmth, however, is expected much farther north, including parts of Idaho, Wyoming and South Dakota. Rapid City, South Dakota may top out in the low to mid-60s.
Most of the records are expected across the Plains, but overall, almost 100 daily warm records — including record highs and record warm lows — could fall from coast to coast on Christmas Day.
The warmth won't be limited to the holiday itself. Hundreds of records could fall throughout the week as spring-like temperatures spread eastward day by day.
This Christmas thaw is the reason many areas that usually count on a white Christmas will be left with bare ground this year.
(MORE:White Christmas Forecast)
What's Causing The Warmup
The unusual warmth is being driven by a strong ridge of high pressure stretching across the central U.S., acting like a lid in the atmosphere. That ridge allows mild air from the South and Southwest to expand northward while keeping colder Arctic air locked well to the north, a setup more typical of spring than late December.
While this spring-like pattern is expected to dominate Christmas Day, it won't last forever. Models are suggesting colder air is likely to return in the days after the holiday, giving us another dose of weather whiplash.
For now, though, the only thing frozen in many places this Christmas, may be the eggnog.
(MAPS:10-Day US Forecast Highs/Lows)
Jennifer Grayis a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.