Which Do You Prefer: A Wet 2018 or a Warm 2019 ?

Although 2019 will finish as a wetter than average year in the Nation’s Capital, it can’t compare to last year, which was DC’s wettest year on record.  There are some interesting comparisons between DC’s predominant weather patterns in 2018 vs. 2019. 

Through December 10, DC has had 40.46” of rain, creating a year-to-date rainfall surplus of 2.69”.  By comparison, there was an annual rainfall surplus of an astounding 23.01” through the same period last year.  Although 2018 got off to a drier than average start through March 31, the final nine months of the year were exceptionally wet.  It’s hard to imagine given how wet last year finished, but Washingtonians actually had an annual rainfall deficit of 1.26” on April 1, 2018, because January and March of last year were drier than average.  

Meanwhile, six of the first seven months of 2019 were wetter than average.  What changed was that the period from August – November saw three drier than average months.  For example, September 2019 was one of the driest in recent memory with only 0.25” of rain.  But Washingtonians experienced the wettest October in more than a decade with 6.66” of rain.  July 2018 and July 2019 each have something in common.  Both months had a day with an exceptional amount of rainfall.  A daily record of 4” occurred in the Nation’s Capital on July 21, 2018, while 3.44” fell on July 8, 2019.  Getting daily rainfall totals of 3” or more is exceptionally rare in the Mid-Atlantic Region absent a tropical system.

This year will finish as much warmer than last year.  Seven out of the 12 months of 2018 were cooler than average and nine were also wetter than average.  By comparison, last month was the first cooler than average month of 2019 in Washington, D.C.  In July 2019, DC residents endured the longest heat wave in nearly three years.  

November and December 2018 were each warmer and wetter than average in the Nation’s Capital.  This trend continued in January and February 2019.  There was a weak episode of El Nino last winter, so having a wetter than average winter was not unusual.  By comparison, there is currently no El Nino or La Nina present, meaning “ENSO neutral” conditions currently exist according to NOAA’s December update.  NOAA’s Outlook for the rest of the winter season is for warmer and wetter than average conditions in the Mid-Atlantic Region.