DC’s wet May eases drought

 

A May day at Glen Echo Park in Maryland

May 2025 has been a wetter than average month in the nation’s capital with 6.70” as of May 28. That’s helped make this DC’s wettest month since July 2022 (7.61”). May is the third wettest month of the year, on average, in Washington, D.C. and this May has certainly lived up to that billing.

Prior to May 1, the nation’s capital had an annualized rainfall deficit of 1.88” for the four-month period of January 1 through April 30. By itself, it isn’t that large an amount spread over four months, but this deficit was on top of DC’s rainfall deficit of 5.43” for the four-month period of September 1, 2024 through December 31, 2024.

These drier than average conditions combined with DC’s warmer than average first few weeks of May exacerbated the widespread moderate to severe drought conditions that had enveloped the DC Metropolitan Area.

However, since May 20, there has been a major shift in DC’s weather pattern. Following the warmer than average temperatures DC experienced on 16 of the first 19 days of May, it has been cooler than average ever since. This cooler than average stretch of weather will prevent May from ranking among DC’s warmest.

The frequent rainfall will also help this May rank among DC’s wettest. Three of DC’s 10 wettest May’s have already occurred in the last 20 years. This year has also gone from having a rainfall deficit on May 1 to having an annualized rainfall surplus today (+1.26”). That’s great news heading into the warmer summer months.

DC’s 15 wettest May’s (Source: NOAA)

1. 10.69” (1953, 1889)
3. 10.66” (2008)
4. 10.60” (1886)
5. 8.87” (1948)
6. 8.73” (2018)
7. 8.05” (2009)
8. 7.77” (1989)
9. 7.73" (2025)
10. 7.06” (2003)
11. 6.99” (1946)
12. 6.97” (1897)
13. 6.80” (1971)
14. 6.73” (1924)
15. 6.33” (1949)

Average: 3.94”