How Cold Can March Get ?

DC Can Still be Quite Cold In March

Although “meteorological” spring officially arrived on March 1, the first half of March can still be quite cold and snowy in the DC Metro Area.  March 2019 has proven as much with a very winter-like start and will actually get even colder as the week wears on.  A persistent, winter-like dip in the jet stream over the eastern United States has allowed colder than average temperatures to envelop the Nation’s Capital among many other cities.

There have been a number of similar events in recent years.  As recently as March 2015, Washingtonians experienced a cold and snowy start to the month with 4.8” of snow on March 5.  That was followed by a high/low temperature of only 30°/15° at National Airport on March 6, significantly colder than the average of 52°/35° for the date.  That was the last time Washingtonians had a high temperature at or below freezing in March.  It was also eerily similar to how March began a year earlier, when a total of 3.8” of snow fell downtown on March 3, 2014 and 4.9” at Dulles Airport.  That was followed by a frigid high/low temperature on March 4 of 29°/-1° at Dulles Airport, which was a record low temperature and the last time March temperatures there fell below 0°.  

The 12.7” of snow that occurred in DC in March 2014 made it the snowiest since 1960 (17.1”).  March 2014 was also DC’s coldest March since 1996.  Both months had an average temperature (combining daily high/low temperatures) of 42.9° in the Nation’s Capital.  Dulles Airport was even colder with an average temperature of 37.4° in March 2014, which became its coldest on record.  It was also the snowiest March on record at Dulles Airport with 19.8”.  

Looking at March’s over a 26-year period (1993 through 2018), the Nation’s Capital has averaged about one day every other year when high temperatures remain at or below freezing.  Over the last 26 years there have been only four days when high temperatures remained in the 20s, with the last such occurrence on March 3, 2009 (29°).  Over the same time period, DC has averaged one day with highs of at least 80° in March.  The last time was on March 1, 2017, with a record-tying high temperature of 80° at National Airport.

Something meteorologists look at when preparing a weather forecast is the trend.  There has been an interesting trend in the Nation’s Capital over the last two years.  March was colder than February in both 2017 and 2018.  While those February’s ranked as DC’s warmest and fourth warmest on record, March in both cases was still colder than average.  

A total of 0.3” of snow has already occurred this month in Washington, D.C. making it the seventh consecutive March with measurable snowfall in the Nation’s Capital.  That’s the longest such streak on record in Washington, D.C. since snowfall records began in 1888. 

Record Lows / Record High Lows (Source: National Weather Service)

March 6

DCA: 10° (1888) / 21° (1901)
IAD: 6° (2015) / 27° (2015)
BWI: 10° (2015) / 21° (1901) 

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March 7

DCA: 13° (1890) / 27° (1932)
IAD: 2° (2015) / 25° (1989)
BWI: 6° (2015) / 26° (1989)