In early November, Washington had six days in a row with highs of at least 70 degrees, the fourth-longest such streak ever observed during the month. It hit at least 65 degrees on 10 straight days, the second-longest such streak.
The mild November helped the fall close as the 13th-warmest on record, with an average temperature of 62.1 degrees.
Although November featured numerous warm, sunny days (22 of 30 days had no measurable rainfall), when it rained it poured. For the first time on record, more than two inches of rain fell on a single day twice.
In all, 6.14 inches of rain accumulated, the sixth-most on record during the month, 2.97 inches above average.
November’s generous rainfall pushed the fall 2020 total to 16.53 inches, tying 2006 as the eighth-wettest on record.
The month was far more notable for its warm extremes than its cold extremes. Only 10 of the 30 days saw highs below 60 degrees, and there was just one day with highs in the 40s.
The fall’s first freeze occurred Nov. 19, which was just one day after the average date between 1981 and 2010.
Here is a summary of the month’s extreme weather:
The abundant warmth and heavy rain events during the month resulted in numerous daily records:
- On Nov. 7, Baltimore tied a record high of 77, while Dulles, which hit 76, topped its previous record.
- On Nov. 8, Dulles tied a record high of 76.
- On Nov. 10, Washington tied a record high of 76, while Baltimore and Dulles set records of 78 and 77 respectively.
- On Nov. 11, Washington set a record warm low temperature of 61.
- On Nov. 11, Washington and Dulles set record rainfalls, receiving 2.02 and 1.21 inches respectively.
- On Nov. 30, Washington, Baltimore and Dulles set record rainfalls, receiving 2.39, 2.74 and 1.38 inches respectively.
November’s weather pattern
The warmth in Washington fit into a milder weather pattern that prevailed over a large percentage of the United States:
Mild weather prevailed despite a strengthening La Niña pattern, which can favor outbreaks of cold air into the Lower 48 states during the late fall and early winter.
The mild weather was a reflection of a much stronger-than-normal polar vortex that kept frigid air bottled up over the Arctic. In response, the jet stream was fast-moving, without major blockages to force cold air south.
There are signs, however, that the prevailing weather pattern may change some during December and that La Niña may have greater influence.
Year to date
After the warm and wet fall, 2020 is now tracking as the third-warmest and second-wettest of the decade:
How was our forecast for November?
A month ago, we projected that November would be volatile, but with temperatures and precipitation near average. While the month did display some volatility, our temperature and precipitation predictions were incorrect. Therefore, we grade our outlook for November a D. At least we didn’t call for a cold and dry month!