A Closer Look at March Weather in DC

March 2015 Snowfall in the DC Metro Area

March is one of the most diverse weather months for much of the United States.  That’s certainly true in the DC Metro Area where accumulating snow, severe weather and summer-like warmth can all occur.  The first third of this month has been on the blustery side with high winds causing the near average temperatures to feel much colder.  Nevertheless over the first third of the month, DC’s average temperature (combining daily high and low temperatures) is 43.1° (0.4° colder than average).

DC’s warmest March on record was in 2012 and third warmest was in 2016.  D.C. has averaged approximately four March days with high temperatures in the 70s, and between seven and eight days in the 60s over the last 24 years.  It also averaged roughly one day with highs in the 80s and one day with high temperatures at or below 32° every other March.  DC residents experienced four days with temperatures in the 80s in March 1998 and March 2012.  By comparison, March 1996 and March 2009 each had consecutive days where temperatures remained below freezing. 

March 2014 was DC’s snowiest March since 1960 and coldest since 1996.  Washingtonians may recall that record snowfall occurred on St. Patrick’s Day in 2014.  A total of 7.2” of snow fell on March 16-17, which made for DC’s tenth largest March snowstorm.  Although DC residents have had accumulating snow in eight of the last 10 March’s, including this month, the last two winters have featured significantly below average snowfall.  

Half of the last 24 March’s have been wetter than average in Washington, D.C.  Washingtonians experienced their driest March on record in 2006 (0.05”) and the second wettest in 1994 (8.45”).  NOAA keeps weather records in the United States and counts the liquid equivalent of snowfall as rain.  In other words, if 2” of snow melts into 0.2” of water, then that would count as 0.2” towards March’s average of 3.48”/rain.

Although severe weather in March is rare in the Mid-Atlantic Region, it does occur on occasion with some notable examples on March 4, 2008 and March 10, 2011.  March severe weather is more common in the Midwest and southeastern United States.  For example, a total of 687 reports of severe weather (including 132 tornadoes) occurred on March 2, 2012 from the Ohio Valley to the Gulf Coast with a total of 30 fatalities.  Also, on March 27, 1994, a deadly tornado outbreak occurred in the southeastern United States with 29 tornadoes that claimed 40 lives in what was dubbed the “Palm Sunday Tornado Outbreak.”

A Good Time to Discuss Severe Weather

Some Facts on the 2002 La Plata Tornado  (Source: WUSA9)

March is often characterized by large swings in temperature across the central and eastern United States.  These large differences in temperature can facilitate the development of thunderstorms.  The DC Metro Area also seed an uptick in the frequency of thunderstorms in the spring.  Check out this article I wrote for the WUSA9 website for some thunderstorm and severe weather basics.

The Start of Spring ?

Although many people consider the March 20 vernal equinox to be the official start of spring, meteorological spring began on March 1 and runs through May 31.  March is a highly variable and transitional weather much in the Nation’s Capital.  March can occasionally feature late-spring like warmth.

Average temperatures in Washington, D.C. range from 51°/34° on March 1 to 61°/42° on March 31.  The warmest March temperature on record in the Nation’s Capital is 93° on March 23, 1907.  The coldest temperature is 4° on March 4, 1873.  The difference between DC’s warmest and coldest observed March temperatures is the greatest of any month.  Over the last 10 years, there have been five warmer and five colder than average March’s.

Washingtonians average 3.48” of rain in March.  Half of the last 20 March’s were wetter and half were drier than average.  March 2006 was the driest on record in Washington, D.C. with only 0.06” of rain.  Meanwhile, March 2014 was DC’s snowiest since 1960 with 12.7”.  Snowfall records date back to the 1887-1888 winter in Washington, D.C. and in 23 of those 130 winters, March has been the snowiest month.  There is a four-way tie for the decade when March was DC’s snowiest month of the year with three in each decade (2010s, 1990s, 1940s and the 1930s).  

Not since 2008 have Washingtonians had a March without any snow.  Since February 2018 was DC’s third warmest on record according to NOAA, an earlier than average peak bloom of the famous cherry blossoms along the Tidal Basin is expected.  The National Park Service recently estimated that peak bloom will occur between March 17 – 20.  That’s compared to the average date of April 4.  The record for earliest peak bloom was March 15, 1990, while the latest peak bloom was April 18, 1958.  Some major factors that can adversely affect the cherry blossoms include episodes of very warm, very cold or very windy weather.

Being a transitional month, March often vacillates between warmer and colder than average weather in the DC Metro Area.  For example, Washingtonians had a temperature of at least 81° on four out of five days from March 27 – 31, 1998, and DC residents also enjoyed 81°/+ warmth on three consecutive days starting March 13, 2012.  In contrast, Washingtonians remained below freezing on consecutive days from March 2 – 3, 2009.  DC residents also had their snowiest St. Patrick’s Day on record in 2014 with 3.9” and a high/low temperature of only 32°/27°.