January Comes to a Frigid Close

January 2019 has been a unique weather month in the Nation’s Capital.  After a warm start, Washingtonians experienced appreciable snowfall followed by milder than average days and a frigid conclusion to the month.  However, not all of that can be seen in the monthly averages.  Through January 30, DC’s average monthly temperature (combining daily high and low temperatures) was 1.8° above average.

Today is DC’s coldest day in more than a year, with an unofficial low temperature of 10° at National Airport.  The last time it was colder was on January 7, 2018 (8°).  Meanwhile, the temperature fell to -2° at Dulles Airport this morning for its coldest temperature since February 24, 2015 (-4°).  High temperatures are poised to remain in the upper 10s and 20s for the second time this month.  Washingtonians experienced a frigid January 21 with a high/low temperature of 24°/15°

If you add January 13’s high temperature of 32°, Washington, D.C. has had three days this month with high temperatures at or below freezing.  None of those dates occurred consecutively meaning there have been several, short-lived outbreaks of frigid air this month.  At the same time, Washingtonians have enjoyed the same number of days with highs of at least 60°.  That includes DC’s fourth warmest New Year’s Day on record with a high temperature of 64°.  It was also DC’s warmest January 1 temperature since 2005 (69° - the record high for the date).  

Following a streak of warmer than average temperatures on 10 of the first 11 days of January, DC had colder than average temperatures on 13 of the final 20 days of the month (including today).  That will produce a near average monthly average temperature when final statistics are in.  There hasn’t be any record cold this month in Washington, D.C. and the two coldest days have both been dry, so some local winter weather enthusiasts would say that was “wasted cold.”  Nevertheless, 11.5” of snow fell in the Nation’s Capital this month, making January 2019 snowier than average.  It’s also DC’s snowiest month, overall, since January 2016 (18.8”).  

January 2019 will also finish as a wetter than average month, with a total of 3.3” of rain (including liquid snow equivalent).  That makes this DC’s wettest January since 2015 (3.73”).  Having a wetter or drier than average January isn’t a strong indicator of what the rest of the year will be like.  For example, January 2016 and January 2017 were each drier than average months, overall, in what were drier than average years in the Nation’s Capital.  However, January 2018 was DC’s fourth driest on record (0.94”) and last year went on to become DC’s wettest on record.  

Similarly, January 2016 was a snowier than average month in the Nation’s Capital, but the rest of the 2015-2016 winter season saw a combined total of only 3.4” of snow in February and March (below the two month average of 7”).  Meanwhile, more snow occurred in DC last March (4.5”) then during the entire 2017-2018 winter season combined (4.3”).