Late August triple-digit heat could hit DC for the first time in 37 years

WASHINGTON — This summer has been an unusually hot one in the nation's capital. June was the second warmest on record and was followed by the fourth warmest July. Despite the sneak peek at fall last week, with lows in the 50s on Aug. 21 and Aug. 22, summer-like heat has returned.

There have already been five days of triple-digit heat so far this summer (once in June with four more days in July), but none in August. The nation's capital hasn't had a triple-digit August day since 2016. Highs will "only" be in the mid to upper 90s on both Monday and Tuesday.

Triple-digit heat on or after Aug. 20 is even more rare in the nation's capital. There have been only six such occurrences of triple-digit heat over the final third of August since weather record-keeping began in 1871. The last such instance was on August 27, 1987, when it was 100 degrees.

Average daily high temperatures fall throughout August in the nation's capital. The average high, for example, on Aug. 20 is 88 degrees and that falls to 86 degrees by the end of the month. The decrease in daily average temperatures combined with the decrease in the amount of daylight. Extreme heat gets more unusual as September gets closer.