DC's record-setting heat

 

DC's torrid summer of 2024

With D.C.'s July 14 record high of 101° at National Airport, the summer of 2024 has already joined some rarified summers of years past.  Meteorological summer reached its midway point today and continues through August 31.  The last six weeks have been exceptionally hot in the nation's capital. 

The July 14 high of 101° at National Airport not only broke the 70 year-old record of 100° from 1954.  It was also DC's second day of triple-digit heat this summer following the June 22 high of 100°.  Prior to June 22, D.C. hadn't experienced any triple-digit heat since August 2016.  It was also D.C.'s first triple-digit heat in June since 2012.  D.C. also set a new record high of 102° this afternoon and that broke the existing July 15 record of 100° from 1988.

Temperatures during the first half of this summer have been largely defined by two major heat waves.  A "heat wave" is loosely defined as a minimum of three consecutive days with highs of at least 90°.  An 11-day heat wave occurred from June 17 through June 27.  High temperatures reached 95° or higher four times in that period with an average daily high/low temperature of 94.3°/73.7° at National Airport.  That was D.C.'s longest June heat wave since 2010. It also helped last month finish as D.C.'s second warmest June, behind only 2010.

Another even more significant heat wave occurred at National Airport from this July 4 through July 11.  Although no triple-digit heat was observed during this period, seven of the eight days featured high temperatures of at least 95°.  Exacerbating the severity of the daytime heat was that it remained unusually warm overnight.  Daily low temperatures remained at or above 80° on four of these eight days.  Average daily high/low temperatures in the nation's capital during this heat wave were 97°/78.4°. That helps illustrate that while July's heat wave wasn't as long as June's heat wave, it was an even hotter period.

Following today's record high of 102° with a potential fourth day of near 100° heat tomorrow, residents of the DMV will get a break from the extreme heat with several days of highs in the mid to upper 80s starting Thursday.