Surprising Trends in D.C. Snowfall

 

January 2016 Blizzard, Bethesda, Maryland

As D.C. area winter weather enthusiasts know, appreciable snowfall has been hard to come by since the record-setting Blizzard of 2016.  There have been only three snowier than average months in the Nation’s Capital during the seven years since then.  That’s resulted in several very long stretches of below average snowfall in Washington, D.C.

Following the January 2016 blizzard, D.C. experienced below average snowfall until March 2018.  That March was a snowier than average month largely due to widespread 3” – 6” snowfall totals on March 21.  This 26-month period had similarities to a 33-month stretch of below average snowfall from February 2000 through November 2002 in Washington, D.C.  Having two or more consecutive winters without a single month of above average snowfall is unusual. 

January 2019 was a snowier than average month in the Nation’s Capital with 11.5”.  It remains the last time a snowfall of at least 10” occurred during a single storm with 10.3” from January 12-14.  D.C. wouldn’t experience another snowier than average month until January 2022.  The stretch of 36 consecutive months was D.C. longest such streak since another three-year streak with below average snowfall from March 1996 – March 1999.

In another unusual turn of events, no accumulating snowfall has occurred so far this winter.  Consequently, over 10 months have passed since the last time accumulating snowfall was measured in the Nation’s Capital.  Although a trace of snow – too little to measure – occurred on December 23, 2022, and January 8, 2023, there’s been no accumulating snowfall in Washington, D.C. since March 12, 2022 (0.9”).

Washingtonians average 4.9” of snow during the month of January, using National Weather Service data from 1991-2020.  While it’s possible a single storm could bring double that amount of snow, the entire winter could still finish with below average snowfall.  Such was the case during the 1998-1999 winter season when March was D.C.’s snowiest month with 8.7”, more than quadruple the monthly average.  Despite being a very snowy March, the 1998-1999 winter finished with 11.6” of snow, or 3.8” below the seasonal average of 15.4” at the time.

Similarly, the 2015-2016 winter season would have finished with less than one-third of D.C.’s annual snowfall average without the January 2016 blizzard.  These facts illustrate that while the Nation’s Capital hasn’t had much snow during the last several years, the weather pattern can change quickly to create favorable conditions for a sizeable snow event. 

Unusual January warmth in the nation’s capital

 

Yesterday was DC’s sixth January day that high temperatures reached the 60s.  That’s more than double the average of between three and four such days over the last 30 years.  It is also the highest such total for the nation’s capital since there were eight days in the 60s in 2018.  

On top of the six unusually warm days, there has been only one cooler than average day so far this year in the nation’s capital.  That’s helped put January 2023 on track to finish among the top five warmest January’s on record.  NOAA’s Climate Prediction Center expects near to above average temperatures to continue for much of next week.  This month should feel particularly warm when compared to last January, which finished 2.9° colder than average in Washington, D.C.

DC's warm January fits a larger pattern that dates back to 2010.  Over the last 12 years, the nation’s capital has seen seven months that set records for warmest: February (2017), March (2012), April (2017), May (2015), June (2010), July (2011), and December (2015).

The summers of 2010 and 2011 were memorable in the nation's capital due to triple-digit heat and record heat. While June 2010 was DC's hottest, July 2010 finished tied for third warmest.  July 2011 was DC's hottest on record and finished with three days of at least 100° heat.  That’s in addition to low temperatures that remained a very oppressive 80°/+ on seven days.

There have also been very warm spring months in the nation's capital in recent years.  March 2012 is a good example, with highs in the 80s on four days.  By comparison, it had only two days with temperatures at or below 32°.  April 2017 was also exceptionally warm with nine days of summer-like high temperatures in the 80s.  May 2015 was also DC's warmest.

December 2015 was a remarkable month in the nation's capital because it had three days with high temperatures in the 70s.  That's compared to only two days of low temperatures that were 32° or colder.  The month also featured 11 days with highs in the 60s that contributed to the average monthly temperature of 56.0°.  That's 9.5° warmer than average and more characteristic of April than December.  February 2017 also became DC's warmest on record.

With January 2023 all but certain to finish among DC’s warmest on record, winter weather enthusiasts haven’t had much to cheer for.  Not only has there been no accumulating snowfall so far this winter, none is in the forecast in the short-term due to an unfavorable weather pattern.

Warmest January’s in the nation’s capital (Source: NOAA)

1.  48° (1950)
2.  46.8° (1932)
3.  43.8° (1937, 1890)
5.  43.6° (1990, 1913)
7.  43.1° (2006)
8.  43.0° (1998)
9.  42.9° (1974)
10.  42.6° (1949, 1933)
12.  42.4° (2020)