DC’s Record Setting November

November 2018 will finish as DC’s first colder and wetter than average November since 2002.  This month also broke DC’s 1877 record (7.18”) for wettest November with 7.57”.  That put 2018 less than an inch away from the 1889 record (61.33”) for wettest calendar year with 60.45” of rain since January 1.

  

The Nation’s Capital averages 3.17” of rain in November, but has more than doubled that amount with 7.57” of rain this month.  That’s more rain than Washingtonians saw during the previous four (2014-2017) Novembers combined.  The Nation’s Capital averages 3.05” of rain in December so setting a new record for wettest calendar year is likely.  DC’s official weather reporting site is National Airport and that’s often important to remember since conditions can sometimes vary quite a bit between National Airport and other weather reporting sites, like Dulles Airport. 

Having a wetter than average November also raised the total of wetter than average months this year to eight.  Only January, March and October were drier than average.  DC Area residents also saw measurable November snow this month for the first time since 1996.  The 1.4” of snow on November 15 is almost triple DC’s November snowfall average of 0.5”.  According to NOAA, Washingtonians have seen more snow this November than in any November since 1989.

November’s warmest day in the Nation’s Capital was November 1 (76°), while this month’s coldest temperature was 28° on November 23.  In fact, the high/low temperature of 35°/28° on November 23 produced a daily average temperature of 31.5° and made for DC’s coldest November day since November 19, 2014.  With a monthly average temperature (combining daily high/low temperatures) of 46.7° through November 29, this month will finish approximately 3° colder than average (49.6°). 

Some may wonder if there is a correlation between a colder and wetter than average November and the upcoming winter season.  Looking at DC’s 10 wettest November’s prior to 2018, seven were also colder than average.  However, only two of the seven subsequent winters were snowier than average (1877-1878 and 1932-1933).  The facts do not support a correlation.  NOAA currently expects near average temperatures and precipitation in December.