What Should DC Expect From November ?

October 2019 finished as DC’s seventh warmest with a monthly average temperature of 64.1° (combining daily high and low temperatures).  That includes DC’s new October record high temperature of 98° that occurred on October 2.  Last month was also DC’s ninth wettest October on record with a “devilish” total of 6.66”.

Two things made last month’s rainfall especially impressive.  First, only 0.14” of rain occurred from October 1 – 15.  But, during the second half of October 2019, an inch or more of rain fell on four different days, giving Washingtonians the third wettest second half of October on record (6.52”).  Ironically, the Nation’s Capital didn’t see any current or former tropical systems in October making such appreciable rainfall remarkable.  It was also much needed as moderate to severe drought conditions enveloped much of the DC Metro Area by early October, given very dry conditions from July 15 – September 30.

There are several parallels between last month and October 2007.  To begin, October 2019 was DC’s first since 2007 to finish among the Top 10 for warmest and wettest October.  Washingtonians also experienced record 90° during each month.  Similar to the dry start to last month, no measurable October rainfall occurred in the Nation’s Capital until October 19, 2007.  Then in a four-day span from October 24 – 27, DC had 6.18” of rain.

November has gotten off to a rather chilly but dry start in the Nation’s Capital, with beautiful weather for the Nationals World Series championship parade yesterday.  Average high/low temperatures in November range from 63°/45° on the first to 52°/37° by the end of the month.  DC’s hottest November temperature on record is 86° on November 1, 1974.  It’s coldest is 11° on November 30, 1929.  Dating back to 1999, 13 of the last 20 Novembers have been warmer than average in the Nation’s Capital.

Washington, D.C. averages 3.17” of rain and 0.5” of snow in November.  Although last November was DC’s wettest on record with 7.57” of rain, 14 of the last 20 have actually been drier than average (including eight straight from 2010 – 2017).  Washingtonians do see measurable snow on occasion in November, such as last November 15 when 1.4” occurred at National Airport.  NOAA’s November outlook is for cooler than average temperatures with near average precipitation in the DC Metro Area.