DC’s volatile December weather

 

A snowy December day (Photo Credit: Paul Laudicina)

The nation’s capital averages 1.7” of snow in December, but measurable snowfall has occurred in only 13 of the last 24 years – including last year.

December 2009 was the snowiest on record in Washington, D.C. (16.6”). Longtime Washingtonians may remember the record December 18-19 snow that year which remains one of DC’s 10 largest snowstorms.

DC residents have experienced seven of the 10 warmest December’s on record since 2011, including the warmest in 2015. December 2015 finished with a total of 14 days with high temperatures in the 60s and 70s, while low temperatures only fell at or below freezing twice with no snow.

However, this December has gotten off to a colder than average start. That doesn’t necessarily mean the rest of the winter will be colder than average. Area residents may recall that following DC’s warmest December in 2015, DC’s fourth largest snow storm occurred in January 2016. At the opposite end of the spectrum was December 1989, which finished nearly 12° colder than average. In addition, 1989 remains DC’s only year that had snow on the ground on both Thanksgiving and Christmas. Meanwhile, the rest of the 1989-1990 winter was warmer than average with below average snowfall. 

The right elements have to come together only once to bring Washingtonians a classic winter storm capable of producing the seasonal average of snow in just one event (13.7”). For example, a sufficiently cold air mass combined with the appropriate storm track close to the East Coast could bring the requisite moisture to the DC Metro that could result in a winter wonderland.

December is the second of five consecutive months with an average of at least 0.1” of accumulating snowfall in the nation’s capital. However, Washingtonians haven’t had a snowier than average December since 2017 or a “white Christmas” since 2009.