Year of the Umbrella Comes to a Close

There have been a number of major weather events in the Nation’s Capital over the course of 2018.  That ranges from DC’s earliest 80° on record on February 21, to record snow in March, and unprecedented rainfall that occurred so frequently from May through December.  The dominant weather headlines in the DC Metro Area has been the record rains of 2018.

Washington, D.C. broke a 129-year-old record for wettest year on December 15, when a daily record 2.55” of rain fell at National Airport.  Several days of rain occurred since then and more is occurring today, making DC’s 2018 rainfall total a record that will be hard to beat in the future.  That stands at 65.80” as of December 30 and could end up finishing more than 5” higher than the 1889 total, 61.33”.

There are several rainfall-related milestones this year.  Nine of the 12 months of 2018 have been wetter than average.  That by itself isn’t that unusual and occurred as recently as 2014.  However, for the first time DC had three months that finished with at least 8.7” of rain.  This year also had 24 days with at least one inch of rain, breaking the previous record of 21 set in 1878.

The plethora of rainy days led to some very wet months in the Nation’s Capital this year, including DC’s sixth wettest May, fourth wettest July, fifth wettest September and wettest November on record.  Weather records in Washington, D.C. date back to 1871.  Having four months rank in the Top 10 for wettest months in a single year is truly remarkable.

While there have been some dry periods in Washington, D.C. this year, they have been few and far between.  January and March 2018 were each much drier than average.  No measurable rainfall occurred in DC from July 1 through July 16.  That makes DC’s 9.73” of rain over the final two weeks of July much more impressive.  Over 40% of that total occurred on DC’s wettest day in nearly seven years, when 4” of rain fell on July 21.  There were 11 consecutive dry days earlier this month and that was noteworthy for being DC’s longest stretch without rain since September 2017.  However, since then, DC has almost doubled the December average of 3.05” of rain with 5.34” as of December 30.

Despite December’s above average rainfall, it has also been a warmer than average month with a monthly average temperature (combining daily high and low temperatures) almost 4° above normal.  In an unusual twist, Washingtonians had measurable snowfall in November for the first time in more than 20 years, with no December snow whatsoever for only the third time in the last 20 years.  The last time Washingtonians had measurable snow in November but none in December was in 1983.