D.C.’s Punishing Heat Waves

 

Washington, D.C. had some memorable July heat waves over the last 10-15 years.  A “heat wave” is defined as a minimum of three consecutive days of 90°/+ heat.

2019:  There was a stretch of 12 consecutive days that reached at least 90° from July 11 – July 22.  D.C.’s hottest temperature during this period was 99° on July 21.  Highs during this 12-day heat wave reached at least 95° five times.  While no record highs were set at National Airport, this heat wave was D.C.’s longest since 2016.

2016:  A 13-day heat wave occurred from July 21 – August 2.  Highs reached at least 95° six times.  The hottest temperature at National Airport was a record-tying high of 100° on July 25.  That was D.C.’s first instance of triple-digit heat since 2012.  This heat wave helped July 2016 finish as D.C.’s seventh warmest on record.

2012:  Although it began in late-June, the majority of an 11-day heat wave continued through July 8.  High temperatures reached at least 100° on five of those days, including four consecutively.  What made matters were widespread power outages that followed the infamous June 29 derecho.  

2011:  There was a 16-day heat wave from July 18 – August 2 (D.C.’s longest since an 18-day heat wave in 1999).  Not only did highs reach 100°/+ on four days, but another 8 days featured highs of least 95°.  The hottest day during this memorable heat wave was 104° on July 29.  That was D.C.’s hottest temperature in nearly 14 years since it was 105° on August 17, 1997.

2010:  The most significant heat wave of the summer occurred from July 14 – July 25.  During this 12-day stretch, the Nation’s Capital had five days with highs of at least 95° with the hottest day being 101° on July 24.  Following a near record high of 99° on July 25, this heat wave came to a rather abrupt end with widespread severe weather across the D.C. Metro Area.