December Gets Underway

 

November 2022 finished as a warmer and drier than average month in the Nation’s Capital for the first time in six years.  That’s with some irony since last month finished tied with November 2016 as D.C.’s 11^th warmest on record.  Such a distinction is fairly significant as weather records in Washington, D.C. date back to 1871.  There has been a high degree of temperature fluctuations over the last two months in the Nation’s Capital as October finished 2.6° cooler than average while last month finished 2.6° above average.

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.

The Nation’s Capital averages 3.41” of rain in December.  Washingtonians can also 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).

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 such as what happened in December 2009.  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.

While there are several rainfall chances this week, no significant wintry precipitation is expected for the D.C. Metro Area.  However, NOAA’s Climate Prediction Center expects a pattern change with colder temperatures for the Nation’s Capital by the middle of the month.  Any rainfall would also be beneficial because D.C. has a rainfall deficit of 3.66” since August 1.  The Nation’s Capital hasn’t had a wetter than average month since July.