April 2018 will be remembered as a cooler and wetter
than average month. That’s good,
however, since the DC Metro Area got some beneficial rainfall. Washingtonians had 3.59” of rain, making this
month D.C.’s second wetter than average month of 2018. Through April 29, D.C.’s average monthly
temperature (combining daily high and low temperatures) is 54.8° or 1.8° cooler
than average.
The latest Drought Monitor Index shows abnormally dry
conditions exist for parts of the DC Metro Area. A small area of moderate drought conditions also
exists within D.C. City limits, making April’s rainfall surplus especially
timely. This month’s 3.59” ranks more
than half an inch above D.C.’s April average of 3.06”. That’s helped reduce D.C.’s rainfall deficit
to 0.63” since January 1. Prior to this
month, the last time Washington, D.C. had an April that was both cooler and
wetter than average was in 2007.
D.C.’s warmest temperature this month was 86° on April
13. By comparison, the temperature fell
to 34° twice on April 5 and April 8. Above
average temperatures have been relatively rare this month. For example, high temperatures in the
Nation’s Capital have been at or below average on all but 11 days since April 1.
April has also been a windy month in the Nation’s
Capital with average wind speeds reaching at least 10 mph on 19 days. Severe weather occurred in parts of central
and southern Virginia on April 15. That
coincided with the 2.01” of rain that Washington, D.C. saw on April 15-16. That was D.C.’s largest two-day April
rainfall total since 2014.
April is the second month of meteorological spring that runs from March 1 through May 31. It is an important transitional weather month for much of North America. With average temperatures that range from a high/low of 62°/42° on April 1 to 71°/52° on April 30, it bridges the gap between chilly March temperatures and the warmer temperatures of May. Some of the DC Metro Area’s most significant severe weather has also occurred during the month of April from the La Plata tornado of 2002 to the severe weather outbreak of April 27-28, 2011.
