Weather Quiz

 

A stellar May day in Montgomery County, Maryland (Photo Credit: Susan Granzow)

True or False.

May 2025 will finish as DC’s first cooler and wetter than average May since 2017.

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”

Beware: Another potentially active Atlantic hurricane season starts June 1

 

Pine Island Beach, Florida

NOAA says there is a 60% chance the 2025 Atlantic hurricane season will be busier than average. 

The May hurricane forecast from NOAA is for a seasonal total of 13 to 19 tropical storms (sustained winds of at least 39 mph), of which 6 to 10 intensify into hurricanes (sustained winds of at least 74 mph), with 3 to 5 of those becoming "major" hurricanes (Category 3 or higher with sustained winds of at least 111 mph). That’s greater than the seasonal average of 14 tropical storms, 7 hurricanes and 3 major hurricanes. 

NOAA's forecast is similar to the Colorado State University forecast that calls for 17 tropical storms, of which 7 becomes hurricanes, with 4 major hurricanes. Both NOAA and CSU cite the same two primary conditions in their respective forecasts. 

Neither El Nino or La Nina conditions are present in the eastern Pacific and Atlantic Ocean Basin. The absence of El Nino in the tropical Atlantic correlates to lower amounts of wind shear than there could be. Wind shear are winds that differ in speed or direction with altitude. According to NOAA’s Climate Prediction Center, there’s a 74% chance these “ENSO neutral conditions” will continue through August and a 50% chance they’ll continue from August through October. 

Also, hurricanes typically require warm ocean water of sufficient depth to develop, commonly at least 80° Fahrenheit to a depth of 200’. Currently, sea surface temperatures are warmer than average in the “MDR” or "Main Development Region" of the Atlantic Ocean. The combination of unusually warm ocean water with a lack of wind shear creates an ideal environment for tropical storm and hurricane development.

Regardless of how many named storms develop, the overall number of tropical storms and hurricanes is less important than where they track. An otherwise quiet season could be very destructive and deadly. For example, the 1992 Atlantic season was relatively quiet with only 7 tropical storms, 4 hurricanes and 1 major hurricane. But that major hurricane was Andrew, which made landfall in southern Florida as a rare Category 5 storm. Andrew was the costliest natural disaster in U.S. history at the time and remains one of the costliest hurricanes on record. Meanwhile, the 2010 season was an active one with 19 tropical storms, 12 hurricanes and 5 major hurricanes, but with no significant impacts in the United States.

The 2025 Atlantic hurricane season officially gets underway on June 1. The first named storm of the season will be “Andrea.”