DC’s November weather – A closer look

 

Fall foliage at its peak in suburban Washington, D.C.

November is the third and final month of meteorological fall and daily average temperatures and the amount of daylight both fall throughout the month.  Consequently, it begins to feel more like winter in the nation’s capital as November wears on.  That’s not to say there haven’t been fleeting moments of unusual November warmth, particularly early in the month.

This week is a good example with several days of above average temperatures that my colleagues and I on the WUSA9 Weather Team are forecasting with highs in the 70s both today and on Thursday.  DC’s warmest average daily high temperature this month occurs on November 1 (64°), so any 70° November warmth is above average. 

While highs in the 70s are above average, they aren’t uncommon in November.  The nation’s capital has averaged between three and four November days in the 70s over the last 30 years, according to NOAA.  That’s the same number of November days that Washington, D.C. has averaged with low temperatures at or below freezing. 

High temperatures in the 80s are less common in the nation’s capital in November with an average of only one every five years.  By coincidence, a record high of 81° occurred at all three DC Area airports one year ago today. 

It's also noteworthy that while six of the last 10 November’s have been cooler than average in the nation’s capital, only one record low has been observed in that time.  A record low of 26° occurred at National Airport on November 11, 2017.  By comparison, four record November highs have occurred in the nation’s capital over the last decade. 

The numbers are even more striking at Dulles Airport where weather records only go back to the 1960s, compared to the 1870s downtown.  Naturally, it was cooler in the nation’s capital the further back in history when there was less of an urban heat island effect.  Weather measurements were also made downtown before National Airport opened during World War II and away the moderating impacts of the Potomac River.

Despite the several cooler than average November’s in recent years, accumulating November snowfall has proven elusive in the nation’s capital.  There has been only one such occurrence since 2000 with a daily snowfall record of 1.4” on November 15, 2018.