A Dramatic Shift in Temperatures

May 2020 has gotten off to a cold start in the Nation’s Capital.  Over the first 12 days of the month, temperatures in Washington, D.C. have been 6.6° below average.  Washingtonians have experienced rare record May cold with above average rainfall.  After highs in the low 60s the last two days, temperatures today will be closer to but still below the May 13 average high of 75°.  Although NOAA’s Climate Prediction Center expects warmer than average conditions in the DC Metro Area over the next few weeks, there’s a fair chance May 2020 will finish cooler than average.

Saturday’s high temperature of 52° at National Airport tied DC’s record low-high temperature for May 9 that was originally set in 1877.  It was more than 20° colder than the average high for that date.  The last time DC residents had a May high temperature colder than 52° was in 1963 when it was only 51° on May 1.  

In fact, all three DC Area airports, National, Dulles and BWI, experienced record low-high temperatures on May 9.  The last time the Nation’s Capital had a record low-high temperature in May was in 2003.  DC’s low temperatures on May 9 and May 10 each fell into the 30s.  Before this month, it had been 15 years since Washingtonians experienced May temperatures in the 30s.

The three days with high temperatures in the 50s so far this month were the highest such total since May 2016.  Obviously, this month has been much cooler than average with slightly more rain than average over its first two weeks.  Both May 2016 and May 2017 were also cooler and wetter than average in Washington, D.C.  

The interesting thing about having such cool weather in May is that it’s hard to stay very cool for long this time of the year.  For example, DC had a high temperature of 58° on May 22, 2016 and it was 83° just two days later on May 24.  Also, on May 12, 2017 DC’s high temperature was a chilly 59°, while only five days later it was a July-like 91°.  Later this week, high temperatures will reach the 80s on Friday.  That will be a welcome relief to those so tired of the cool weather so prevalent over the last couple of weeks.