March Surprises

The dusting of snow Washingtonians saw this morning serves as a reminder that March often sees a high degree of variability in the weather.  Wednesday was the first 80-degree day in the Nation’s Capital since early November and, less than 48 hours later, some area residents woke up to a dusting of snow.

March is the first month of “meteorological spring.”  March 1 has average high and low temperatures of 51/34 degrees in Washington, D.C.  But, by March 31, the average high and low temperatures rise to 61/42 degrees.  National Weather Service data indicates Washington, D.C.’s warmest March temperature on record is 93 degrees, which occurred on March 23, 1907.   Meanwhile, March’s coldest temperature in the Nation’s Capital was 20 degrees, which occurred twice in the late 1800s. 

(Modern weather records are kept at National Airport since it opened in 1941.  The warmest March temperature to occur at National Airport is 89 degrees on March 12, 1990.  National Airport’s coldest March temperature is 14 degrees that most recently occurred on March 8, 1986.)

March precipitation can take many varieties.  While March averages 3.48” of rain, Washingtonians also average 1.3” of snow.  The Nation’s Capital has had measureable snowfall during 11 of the past 20 Marchs.  In fact, many area residents may recall that there were three consecutive snowier than average Marchs starting in 2013.  With 12.7”, March 2014 was DC’s snowiest March since 1960 and was the snowiest on record at Dulles Airport (19.7”). 

Equally impressive is the fact that two of DC’s warmest Marchs have occurred in the last five years.  March 2012 was the warmest on record, with an average monthly temperature in Washington, D.C. of 56.8 degrees (10 degrees warmer than average).  Last March was the fourth warmest on record.  This winter has featured frequent record warmth, such as the longest January streak of above freezing temperatures (20 consecutive days) and warmest February on record.  That led the National Park Service (NPS) to forecast a possible record for earliest peak bloom of the famous cherry blossoms along the Tidal Basin.

The existing record for earliest peak bloom is March 15, 1990.  The NPS forecast this year is for peak bloom to occur between March 14 and March 17.  The NPS defines “peak bloom” of the cherry blossoms as when 70% of the blossoms along the Tidal Basin are open.  Last year, the blossoms reached peak bloom on March 25.   However, peak bloom didn’t occur until April 10 following the snowy 2013-2014 winter.  That helps illustrate that March weather often oscillates between warm and dry to cold and snowy.