A closer look at December’s wild weather

 

A view of National Harbor

This December will finish as DC’s coldest since 2010. Although it will also finish as a drier than average month, Washingtonians still experienced the highest December snowfall total in eight years.

The first 17 days of December were colder than average in the nation’s capital. The coldest day was December 15 with daily high/low temperatures of 29°/18°. While nine days since December 18 were warmer than average, this month will still finish more than four degrees colder than average. With a monthly average temperature of 37.5° as of December 30, this month will be DC’s coldest since 2010 (34.6°).

December will also finish as a drier than average month with only 1.77”, well below the monthly average of 3.41”. This month’s wettest day was December 2 with 0.86” of rain and a high temperature of only 42° (11° below average). Only 1.5” of snow fell this month. While below DC’s December average of 1.7”, it was still the highest monthly total since 2017 (1.9”). 

New Year’s Eve will feature colder than average temperatures in the nation’s capital. That will end DC’s recent trend for warmer than average weather on December 31 that lasted from 2018 – 2024. Measurable rainfall also occurred on four of the last seven New Year’s Eves in the nation’s capital.

As a whole, 2025 will finish as a drier than average year with a rainfall deficit of more than 6” at National Airport. This will be DC’s third consecutive drier than average year. Despite an unusually cold December in the nation’s capital, this year will also finish as DC’s tenth consecutive warmer than average year due to a very warm March, April and July.

New Year’s Eve forecast for D.C.

 

A festive time of year in Washington, D.C.

The weather forecast for New Year’s Eve is often of special interest since so many people plan to be out celebrating. The average high/low temperatures in the nation’s capital on December 31 are 46°/32°, according to NOAA.

Washingtonians have enjoyed a streak of seven consecutive warmer-than-average New Year’s Eves. The last time it was colder than average on December 31 was in 2017 during a stretch of frigid weather. 

DC’s high/low temperatures on December 31, 2017, were only 23°/18°. It was one of nine days between December 28, 2017 and January 7, 2018, that daily high temperatures remained at or below freezing. This remains one of DC’s coldest stretches in recent memory that coincided with the New Year’s holiday.

By comparison, DC’s high/low temperatures on December 31, 2024, were a relatively balmy 63°/40°.  DC’s record high on December 31 is 70° and occurred in 1970. More recently, it was 67° on December 31, 1992. DC’s record low on December 31 is -13° from 1880.

Aside from being mild on recent New Year’s Eves in the nation’s capital, three of the last four also featured measurable rainfall. Fortunately, while damp, no record rainfall occurred in Washington, D.C. on December 31 in recent years. DC’s wettest New Year’s Eve was in 1975 with 1.68” of rain. There hasn’t been any snow on New Years Eve in recent years across the DMV (D.C., Maryland and Virginia). DC’s snowiest December 31 on record occurred in 1970 (4.9”).

This New Year’s Eve will be colder than average for the first time in eight years and will also be dry. 

Weather Quiz

 

A winter's day in Washington, D.C.

When was the last time high temperatures in Washington, D.C. remained below freezing on New Year’s Eve?

A. 2022

B. 2017

C. 2003

D. 1998

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.”