Sweat Ceiling 2011

Reagan National Airport (DCA) dropped to a mere 83 degrees this morning, which - barring a cooling thunderstorm this evening - will set a new record high minimum temperature for the date. The previous record was 81 set in 1987. Even more impressive, that steamy 83-degree low (assuming it stands) would tie for the second warmest low all-time in Washington, D.C. (since records began in the late 1800s).

Count of low temperatures at or above 80 degrees by year in D.C. 2011, not shown, has two so far (including today). (Ian Livingston)

Capital Weather Gang’s Ian Livingston reports the warmest low on record in DC is 84, set July 16, 1983. There have been 38 days (including today and yesterday’s low of 80) 80+ lows since daily records began in 1872. Before 1930, there were only 3, and they all happened in 1876. Interestingly, Washington, D.C. has twice as many 80+ lows in the last two years (6) than the entire period from 1872-1930.

Dulles Airport, which fell to 76 degrees, is also likely to set a record high minimum for the date (previous 75 in 1969) but not for the month or all-time (78 from 2010). Baltimore Washington International (BWI) airport appears to have bottomed out at 81 and tied its daily high mimimum temperature record from 1885. Its record high minimum temperature all-time is 83 set in 1930.

Of additional interest, last night at 9 p.m. the dew point - a measure of humidity - rose to 81 degrees at DCA. While dew point records only go back to 1962, that reading would tie for the second highest on record. As we previously reported, the dew point has reached 82 degrees at DCA on several occasions.

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