Following a Cold November, December Gets Underway

 

November 2021 was a colder and drier than average month in the Nation’s Capital.  Washingtonians finished with only a third of November’s rainfall average or 0.98”.  That made for D.C.’s third November over the last decade with less than an inch of rain.  To add to that, temperatures were below average on 20 out of 30 days last month as November finished 2° cooler than average.  It was the fourth time in the last five years November was colder than average in Washington, D.C.

Meteorological winter officially got underway on December 1 and continues through the end of February.  Average daily temperatures fall throughout December, according to NOAA.  D.C.’s average high/low temperatures range from 53°/38° on December 1 to 44°/30° on December 31.  D.C.’s warmest December temperature on record is 79° (December 7, 1998), while its coldest December temperature is -13° (December 31, 1880).  Eight of the last 10 Decembers have been warmer than average in Washington, D.C.  D.C.’s warmest December on record occurred relatively recently in 2015.

The Nation’s Capital averages 3.41” of rain in December.  While nine of the last 20 December’s have been wetter than average, seven of the last 20 have been snowier than average.  Washingtonians can expect an average of 1.7” of December snowfall (2.8” at Dulles Airport).  However, nine of the last 10 Decembers have had below average snowfall, with 2017 being the lone exception.  D.C.’s wettest December (7.56”) occurred in 1901 and driest (0.19”) in 1889.  By comparison, D.C.’s snowiest December occurred in 2009 with 16.6” (due to one of D.C.’s largest winter storms on record). 

These statistics help illustrate that December’s weather can have wide fluctuations from one year to the next.  The right ingredients need to come together merely once to produce a large winter storm.  However, in this La Nina winter, NOAA’s winter outlook is for warmer than average temperatures with near average precipitation.  Many of D.C.’s snowiest winters have occurred during El Nino winters with 1995-1996 being the notable exception.

Although there are several rainfall chances next week, no significant rainfall or wintry precipitation is expected.  That’s not to say the weather during the second half of the month won’t shift, but NOAA predicts above average temperatures will continue during the next one to two weeks for much of the eastern United States.