An arctic air mass and fresh snowpack allowed temperatures to plummet overnight, especially away from the city.
Dulles Airport dipped all the way down to -2, its coldest temperature since -9 on February 6, 1996 (that year it dipped below zero three times at Dulles. The other dates were Jan. 9: -2 , Feb. 5: -10). Even so, it did not break the record for today: -4 from 1978.
At Reagan National Airport, it was 14 degrees warmer thanks to more clouds, its proximity to the river, and urban structure. Its low was 12 degrees, a far cry from the record of 0 from 1936.
BWI, which plunged to 5 degrees, came a little closer to its record low – also 0, from 1936.
Temperatures have quickly recovered, with noon readings into the 20s at all three airports.