Washington closed out 2019 and the 2010s with a warmer- and wetter-than-normal December. The mild month helped 2019 rank as the third-warmest year on record in Washington.
Every month in 2019, except for March and November, was warmer than normal. The annual average temperature of 60.6 was 2.4 degrees above normal (58.2 degrees). Only 2012 and 2017, with annual average temperatures of 61.5 and 60.8 degrees, were warmer.
Seven of the 10 warmest years on record in Washington, since 1871, have occurred since 2011, and all of the top 10 have occurred since 1990.
December’s average temperature of 42.3 degrees was 2.5 degrees warmer than the 30-year average and the 27th-warmest since 1871.
The total precipitation of 3.28 inches was 0.23 inches wetter than normal and ranked as the 64th-wettest December. Snowfall was 0.4 inches, 1.9 inches below normal.
Although December will go on record as warmer than normal, the month was split, with the first two-thirds featuring near- to below-normal temperatures but the final third abnormally mild.
The monthly temperature range was 45 degrees, with the highest temperature hitting 67 degrees last week (on Dec. 28) and the lowest temperature a chilly 22 mid-month. Here are the numbers:
No records were set in Washington or Baltimore in December, but Dulles reported two for mere traces of snow on Dec. 2 and 4, tying marks set in 1987 and 2016.
2019, compared with the past decade
December mimicked the rest of the calendar year, as well as the decade, in finishing warmer and slightly wetter than normal.
2019 ranked as the third-warmest of the 2010s (and, as previously noted, the third-warmest on record dating to 1871) and every year in the past decade was warmer than the 30-year average of 58.2 degrees:
The total annual precipitation of 42.34 inches was about 2.6 inches wetter than average and ranks right in the middle of the 2010s. Six of the past 10 years were wetter than the 30-year average (39.74 inches), most notably 2018, the wettest year on record: