DC’s warm and wet start to May

 

NOAA's Temperature Outlook for the week of May 22

May has gotten off to a warm and wet start in the nation’s capital. Rain fell on 11 of the first 14 days of the month for a total of 4.45” (already above DC’s May average of 3.94”). The rain has been especially welcome considering the ongoing drought conditions in the Mid-Atlantic Region. All but three days have also been warmer than average.

Some may wonder if a warmer and wetter than average May offers some clues to what the upcoming summer weather might be like. Last May, for example, was both warmer and wetter than average in the nation’s capital.  Not only did May 2024 finish more than two degrees warmer than average, but was also a rainier than average month. That was beneficial since the summer of 2024 finished as DC’s third warmest, but was also 1.33” drier than average.  

May 2018, 2019 and 2022 were also warmer and wetter than average in the nation’s capital and gave way to warmer than average summers. However, those summers were each wetter than average in the nation’s capital, unlike last summer. 

May 2014 was also warmer and wetter than average in Washington, D.C. But both July and August were cooler than average in 2014 and that offset DC’s warmer than average June.

Having a cooler than average summer in the nation’s capital has become rare in recent years.  Eight of the last 10 summers have been warmer than average in Washington, D.C. Only two have been drier than average over the same time period. This helps illustrate that while a warmer and wetter than average May could foreshadow a warm and wet summer in the nation’s capital, there’s no direct correlation.

NOAA’s Climate Prediction Center expects May 2025 to finish as a warmer than average month with near average monthly rainfall. However, the 8-14 day outlook issued for the week of May 22 shows they’re expecting cooler and wetter than average weather to envelop the Mid-Atlantic Region. DC’s first half of May has been so much warmer than average that a period of cooler than average weather late in the month shouldn’t be enough to prevent it from finishing warmer than average.

NOAA’s recently issued three-month outlook for June, July and August is for warmer and wetter than average weather for the Mid-Atlantic Region.

NOAA's Summer Temperature Outlook