DC’s Second Snowiest Month ?

The Nation’s Capital is colder than average today for the first time since December 12.  Temperatures this morning fell below freezing for the first time since December 26.  Winter weather enthusiasts should be pleased with this change in the weather pattern from to typical mid-January weather.  While not unusually cold, the weather over the next few days will only feel especially cold because of how mild it has been: the first nine days of January finished 10.3° above average.

Sufficiently cold temperatures are obviously one of the two major ingredients for snow – along with a storm that brings precipitation.  DC Area meteorologists, like my colleagues and I on the WUSA9 Weather Team, are watching the latest model runs as the first winter storm of 2019 in the Mid-Atlantic Region draws closer this weekend.  January is DC’s second snowiest month with an average of 5.6” (February averages 5.7”).  The last time Washingtonians had an inch or more of snow in January was on January 30, 2017 (1”).

November 2018 finished 3.1° colder than average in the Nation’s Capital and saw DC’s most significant snowfall since 1989.  By comparison, December 2018 finished 3.8° and became only the third December in the last 20 years without any snowfall.  This was the first time since 1983 that Washington, D.C. had accumulating snow in November with no measurable snowfall in December.

Going from a milder than average December 2018 and start to January to a more winter-like pattern is quite common.  As recently as the 2015-2016 winter season, Washingtonians experienced a huge swing between DC’s warmest December on record and the belated arrival of winter.  The 2015-2016 winter season also set a record for the latest in the season that the first measurable snowfall occurred in Washington, D.C. (i.e., 0.3” fell at National Airport on January 17, 2016).  That was nearly two months later than the first snow of the 2018-2019 winter season that occurred on November 15, 2018.  

This weekend’s storm is hardly going to be a record-setting storm, unlike what occurred in January 2016.  The epic January 2016 storm helped make it DC’s snowiest January (18.8”) since 1996.  That would have been hard to envision considering the very mild six-week period from December 1, 2015 through January 10, 2016.  

The six-week period from December 1, 2018 to January 9, 2019 was also largely warmer than average.  This serves to illustrate that snow and cold can occur relatively quickly after an extended period of winter warmth in the DC Metro Area.  Snow lovers shouldn’t fret that this weekend’s anticipated storm isn’t expected to be a record-setter because accumulating snow can occur well into March.  For example, the month of March was DC’s snowiest month of the winter season during the 2012-2013, 2013-2014 and 2017-2018 winter seasons.