A closer look at December snowfall

December snow in Montgomery County, MD (Photo Credit: Susan Granzow)

The December 5 snowfall total of 1.1” was DC’s largest December snowfall since 2017. It also made this the third consecutive December with accumulating snowfall in Washington, D.C.

The nation’s capital averages 1.7” of December snowfall. DC’s snowiest December on record occurred in 2009 (16.6”), and has been followed by a prolonged period of below average December snowfall. It used to be DC’s third snowiest month of the year, but has since been replaced by March. March is actually the only month DC's snowfall average has increased over the last decade (from 1.3" in 1981-2010 to 2.0" from 1991-2010).

If this December ends up with above average snowfall, it would not only be DC’s first in eight years, but would also be only the second snowier than average December since 2010. One of the reasons behind DC’s relative lack of December snowfall in recent years is that 11 of the last 15 December’s have been warmer than average.

Washington, D.C. averages 13.7" of annual snowfall, according to NOAA. That's based on NOAA's running 30-year average that’s updated every decade. The current 30-year average was updated to reflect the period of 1991-2020, which replaced the previous data set of 1981-2010. DC’s previous annual snowfall average was 15.4”.

While the nation’s capital is due for appreciable December snowfall, how much snow actually falls in December has little bearing on the upcoming winter season. For example, December 2015 was DC’s warmest on record, with more days highs were in the 70s than lows were at or below freezing, but was followed by the record January 2016 blizzard. DC’s record-setting 2016 storm remains tied for the fourth largest snow event with 17.8” at National Airport.