How Does This Winter Rank ?

The end of meteorological winter has arrived.  The three month period of December, January and February comprise “meteorological winter.”  NOAA uses a running 30-year average (1980-2010) that’s updated every decade to determine what average temperatures and precipitation amounts are in Washington, D.C.

The 2017-2018 winter season could be divided into roughly two different halves with respect to temperature.  The period from December 1 through January 15 was exceptionally cold in the DC Metro Area.  That includes an 11-day stretch where temperatures remained at or below freezing on nine days (December 28, 2017 – January 7, 2018).  Despite the frigid temperatures, only 2.7” of snow occurred during this six-week period.  That speaks to the larger trend of dry weather from September 2017 through January 2018, when the Nation’s Capital had a rainfall deficit of more than nine inches.

Following DC’s driest January since 1981, moderate to severe drought conditions enveloped almost the entire DC Metro Area earlier this month.  Fortunately, a dramatic change in the weather pattern developed with measurable rainfall on 15 of the first 25 days of February.  Despite this, February 2018 has also been significantly warmer than average and that has meant below average snowfall. 

January 2018 had a mild second half with above average temperatures on 11 of the final 15 days.  That warmer than average trend continued into February, as this month is poised to finish as the third warmest on record in Washington, D.C.  In addition, the high temperature of 82° on February 21 was not only the earliest in the year 80° warmth occurred, but was also DC’s first 80° February day since February 28, 1948.

Despite this flip flop from cold and dry over the first half of the 2017-2018 winter season to warm and rainy for much of the second half, the lack of snowfall has persisted.  A total of only 3.3” of snow fell in Washington, D.C. this season or roughly 20% of the seasonal average of 15.4”.  

Washingtonians longing for snow shouldn’t give up hope altogether for seeing a little snowfall.  While last winter was also warmer and drier than average in the Nation’s Capital, March 2017 was snowier than average with two inches at National Airport.  Despite the expected cooler and wetter than average start to March 2018, NOAA says there is a 33% chance that it will feature warmer than average monthly temperatures in the Nation’s Capital and near average precipitation. 

Weather Quiz

True or False.

With 3.3” of snow the entire winter, the 2017-2018 winter is the third consecutive winter season with below average snowfall in Washington, D.C.

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Answer to February 14 Weather Quiz question.

B.  Norfolk, Virginia saw 13.1” of snow in January 2018 that is roughly four times the amount Washingtonians had the entire 2017-2018 winter season (3.3”).  In a rare set of circumstances, Atlanta (4.7”) and Birmingham (4.0”) also saw more snow than the Nation’s Capital this winter.

DC's Warm and Wet February

Not only was February 2017 DC’s warmest on record, it was also the sixth driest with only 0.68” of rain.  That’s roughly 25% of DC’s February average of 2.62”.  Similar to last year, this month will finish among the Top 5 warmest February’s.  However, unlike last year, February 2018 will rank among DC’s wettest.  That’s excellent news for DC area residents who have been experiencing very dry conditions over the prior several months.

Through February 25, Washington, D.C.’s average monthly temperature at National Airport is 44.8°.  Since February 10, all but three days have been warmer than average in the Nation’s Capital.  That includes seven days with temperatures of at least 65°, including the first 80° February temperature in the Nation’s Capital since 1948.

The Nation’s Capital had a rainfall deficit of more than 17” from August 2015 through January 2018.  During that time, DC had below average monthly precipitation in 24 out of 30 months.  In particular, from September 1, 2017 through January 31, 2018 when DC’s rainfall deficit was more than nine inches.  Consequently, much of the DC-Baltimore corridor was experiencing moderate to severe drought conditions earlier this month.

Fortunately, February 2018 has been exceptionally wet with measurable rainfall on 15 of the first 25 days of the month.  With 4.79” of rain as of February 25, this has already been DC’s wettest February since 2003.  As wet as this February has been, only 0.2” of snow occurred and that’s because it has been such a warm month in the Nation’s Capital.

This month’s wet spell has led to improvement in the drought conditions across the Mid-Atlantic Region.  Since the drought conditions occurred outside the growing season, they didn’t have the same impact that they could have.  Given the shift between the very dry month of February last year and the rainy February 2018 in the Nation’s Capital, it’s worth pointing out that DC’s hasn’t had consecutive wetter than average February’s since 1981-1986, according to NOAA.  Also, Washingtonians are experiencing their third consecutive warmer than average February for the first time since 1997-2002.

Top Ten Warmest February’s in Washington, D.C.  (Source: NOAA)

1.  47.7° (2017)

2.  46.9° (1976)

3.  45.2° (1990)

4.  44.7° (1997)

5.  44.4° (2012)

6.  43.8° (1984, 1949)

8.  43.7° (1981)
9.  43.5° (1954)

10.  43.4° (1998, 1890)

D.C.’s Top Ten Wettest February’s (Source: NOAA)

1.  6.98” (2003)
2.  6.84” (1884)
3.  6.47” (1897)

4.  6.17” (1899)
5.  5.71” (1961, 1939)
7.  5.62” (1979)
8.  5.44” (1971)
9.  5.32” (1903)
10.  5.31” (1896)

11.  5.27” (1972)
12.  5.26” (1900)
13.  5.23” (1996)
14.  5.09” (1882)
15.  5.08” (1883)
16.  4.72” (1902)

Record February Warmth !

This week has featured dozens of record-setting daily high temperatures across the eastern United States from Florida to Maine.  In addition, monthly record high temperatures were set in cities such as Tampa, New York City among a number of other cities.  Earlier this week, the DC Metro Area had temperatures more characteristic of early June than late February. 

High temperatures at National Airport reached 78° and 82°, respectively, on February 20-21.  It was also the first case of consecutive February days with temperatures of at least 78° in the Nation’s Capital.  The high temperature of 82° on February 21 also became the earliest 80° temperature on record in Washington, D.C., surpassing the old record of February 25, 1930 (84°).  It was also DC’s warmest February day since February 28, 1948 (82°).  It’s incredible to consider this warmth when 82° isn’t even DC’s average high until June 6.

Dulles Airport also set a record high of 80° on February 21, which was also a new monthly record high temperature.  It broke the previous record of March 8 for earliest 80° temperature by more than two weeks.  As warm as February 2018 has been, last February remains the warmest on record in the Nation’s Capital.  Washingtonians had a total of five days with temperatures in the 60s and six days in the 70s last February, compared to six days with temperatures of at least 60° so far this month.

The Nation’s Capital has averaged one February day with highs in the 70s and nearly three days of at least 60° since 1993.  That helps illustrate how unusual the warmth of last February and this February has been in the DC Metro Area.  This month’s average temperature (combining daily high and low temperatures) through February 22 is 44.3°.  NOAA expects warmer than average weather over the final week of the month, so February 2018 is well-positioned to rank as one of DC’s warmest.

February 2018 has also been wetter than average and that’s welcome news for Mid-Atlantic residents.  Following the fourth driest January on record, moderate to severe drought conditions had enveloped much of the DC Metro Area at the start of February.  However, with the wettest February in the Nation’s Capital since 2003, there has been significant improvement in the drought conditions.  However, much to the chagrin of DC Area snow enthusiasts, only 0.2” of snow has occurred this month.  That makes February 2018 the third consecutive February with below average snowfall.

Top Ten Warmest February’s in Washington, D.C.  (Source: NOAA)

1.  47.7° (2017)

2.  46.9° (1976)

3.  45.2° (1990)

4.  44.7° (1997)

5.  44.4° (2012)

6.  43.8° (1984, 1949)

8.  43.7° (1981)
9.  43.5° (1954)

10.  43.4° (1998, 1890)