Long-lasting December cold gives way to a mild Christmas

 

NOAA expects warmer than average weather for late-December

The first half of December was DC’s coldest since 2005. DC residents didn’t experience a warmer than average day until December 18. That combined to make the first 17 days of this month nearly nine degrees colder than average. Unlike December 2005 that experienced more colder than average weather through December 23 in the nation’s capital, a major pattern shift will occur during the upcoming week for much of the United States.

NOAA’s Climate Prediction Center expects warmer than average weather to dominate much of the United States, including the DMV (D.C., Maryland and Virginia) for the remainder of the year. That will prevent December 2025 from ranking among DC’s coldest, but this month could still finish with colder than average temperatures given the prolonged stretch of colder than average weather to start the month.

DC’s coldest day so far this month was December 15 with a high/low of only 29°/18° at National Airport. That was also DC’s coldest overall December day since Christmas Eve 2022 (22°/9°). This December 15 was also the first time a high temperature remained in the 20s during the first half of December since December 14, 2010 (28°).

There have been other colder than average December’s in the nation’s capital since 2005. Besides being colder than average, there’s something else that December 2009, December 2010 and December 2017 all have in common. Those months were each snowier than average in the nation’s capital. In fact, December 2009 remains DC’s snowiest on record.

This month will not join those as being snowier than average in the nation’s capital. A total of 1.5” of snow has fallen since December 1, near the monthly average of 1.7”. However, no more accumulating snowfall will occur this month. This month’s snow total of 1.5” will still finish as DC’s highest December total since 1.9” occurred in 2017.

Longtime Washingtonians know December temperatures and snowfall aren’t a reliable indicator of what the rest of the winter will be like. For example, December 2015 was DC’s warmest on record, but gave way to a colder than average January that saw the record-setting “Blizzard of 2016.”