Dangerous August Rain Events

 

August has seen a number of significant rain events over the last two decades.  Some were due to decaying tropical systems, while others occurred during severe weather events. 

2021: Last August finished as D.C.’s ninth wettest on record with a total of 9.07”.  Almost half of that rain fell on two days.  A total of 2.38” of rain fell at National Airport making last August 14 D.C.’s second wettest on record.  Another 2.28” occurred on August 20 and was the third wettest such day in the Nation’s Capital.  Both rainfall totals coincided with severe weather in parts of the D.C. Metro Area.

2020: The tropical Atlantic gets a lot busier during the month of August and the 2020 season had more named tropical systems than any other on record.  The second hurricane of the season, Isaias, was a Category 1 hurricane when it made landfall in North Carolina on August 3.  It brought severe weather and record rainfall to the D.C. Metro Area on August 4.  A total of 2.48” fell at National Airport, 1.87” at Dulles Airport and 2.32” at BWI Airport.  Several confirmed tornadoes also occurred in southern Maryland, central Virginia and on the Eastern Shore from the remnants of Isaias.

2018: A severe weather outbreak on August 21 brought reports of wind damage across parts of Maryland and Virginia.  While no tornadoes occurred, National Airport had a daily rainfall record of 2.46”.  This was significant since it was one of 24 days in 2018 that an inch or more of rain fell in the Nation’s Capital.  Washington, D.C. had its wettest year on record in 2018 with 66.28”.

2011:  Hurricane Irene made landfall as a Category 1 hurricane on August 27 and brought significant impacts to the Mid-Atlantic Region and northeastern United States.  A two-day storm total of 3.83” was recorded at National Airport on August 27-28.  It contributed more than a third of D.C.’s August 2011 rainfall total of 8.92”.  August 2011 was D.C.’s rainiest August since 1967, according to NOAA.