FOR WASHINGTON DC...MEASURED AT REAGAN NATIONAL AIRPORT...DCA...
THE AVERAGE WINTER TEMPERATURE OF 43.4F RANKS AS THE 3RD WARMEST
WINTER... DEC-FEB...ON RECORD BEHIND ONLY THE WINTERS OF
1931-32... 44.6F AND 1889-90...44.3F.
FOR BALTIMORE MD...MEASURED AT BWI THURGOOD MARSHALL AIRPORT...BWI...
THE AVERAGE WINTER TEMPERATURE OF 40.7F RANKS AS THE 7TH WARMEST
WINTER ON RECORD...THE WARMEST WINTER SINCE 1949-50. THE WARMEST
WINTER IN BALTIMORE WAS 1931-32...45.3F.
FOR DULLES AIRPORT...IAD...
THE AVERAGE WINTER TEMPERATURE OF 40.1F RANKS AS WARMEST ON
RECORD...BREAKING THE PREVIOUS WARMEST WINTER OF 39.8F SET IN
2001-02. THE PERIOD OF RECORD AT DULLES GOES BACK TO 1962.
1 AM Update: Woot! A high temperature of 56° just before 11 pm rounds up the winter average to 43.4°.
10 PM Update: A temperature of 55° at this hour puts the winter average within 0.005 of rising by another 0.1° to 43.4°.
5 PM Update: The exact final result may depend on how the National Weather Service accounts for leap year, but today's preliminary high as of 4 pm is 52°, which virtually locks in the winter average at 43.3°. Since a further rise of 2° on southerly winds through the evening is not out of the question, the average could actually bump up, as noted below.
With a 2 pm temperature of 51°, following a jump of 6° in the previous hour, and an overnight low of 40° on Leap Day, Washington, DC has maintained a 2011-12 winter average temperature of 43.3°, which edges out 2001-2002 by 0.1° as the 3rd warmest winter in over 140 years of climate history. A further increase of just 3° in this afternoon's temperature would raise the final seasonal average by another 0.1°. On the other hand, because of rounding, it would require a highly-unlikely drop of at least 7° in the daily low (to 33°) before midnight to reduce the average by 0.1°.
Although March snow is not completely out of the question (see "Not the March of the Penguins"), this winter is also the 3rd least snowy on record.
Images (click to enlarge): Washington's 10 warmest winters vs. 2011-12 average to date (through 4 pm February 29) and 10 lowest seasonal snow totals, CapitalClimate charts from National Weather Service data