Summer Arrives in the Nation’s Capital!

 

Area pools will be opening for the season soon

The first half of May 2021 was both cool and dry in the D.C. Metro Area.  However, there has been a major shift in the weather pattern over the last week that has left the Nation’s Capital feeling more like summer.

Washingtonians had a monthly average temperature 2.7° cooler than average through May 18.  There was a dramatic shift since then with six warmer than average days over the last week.  There were three days in the 90s since May 20 and that’s helped the monthly average temperature quickly rise to being within 0.5° of average.

This month has also been quite dry with only 1.03” of rain as of May 25.  There are several rain chances over the last few days of May, so that number is all but certain to increase.  That’s a good thing since if May were to end today, it would finish as D.C.’s driest since 1986.  Washington, D.C. has had less than 2” of rain in May only three times in the last 20 years, most recently in 2015.

May 2015 was a unique weather month as it finished as D.C.’s warmest on record.  It was also an exceptionally dry month with only 1.92” of rain – roughly half the average.  Having a warm and dry May isn’t a good harbinger of what the upcoming summer will be like.  That’s because rainfall from scattered showers and thunderstorms during the summer months in the Mid-Atlantic Region is often spotty and unreliable.

May 2020 was an exception to that rule.  Last May was cooler and drier than average in the Nation’s Capital for the first time since 2006.  However, last summer was warmer and wetter than average.  That was in large part due to D.C.’s record number of 90° days last July (28) in conjunction with several exceptionally wet days.  There was a total of six days last summer that had 1”/+ of rain, including three days with at least 2” of rain. 

The Nation’s Capital has a 2021 rainfall deficit of nearly 2”, so any rainfall would be beneficial.  That’s not what beachgoers want to hear heading into Memorial Day weekend, but there are several rain chances during the next few of days.  May 2021 could finish with near average temperatures and rainfall.  NOAA’s Climate Prediction Center is expecting a warmer and wetter than average summer in the Mid-Atlantic Region.