Ranking July 2016

This July will finish among the hottest on record in the Nation’s Capital despite getting off to a remarkably cool start.  Washingtonians experienced 90-degree heat on 18 out of 19 days through July 31.  That includes Washington, D.C.’s first day of 100-degree heat in nearly four years when the temperature climbed to the century mark on July 25.  Baltimore and Dulles Airport also saw their first 100-degree temperatures since 2012.  

According to the National Weather Service, Washington, D.C. officially had 23 days at or above 90 degrees at National Airport since July 5.  That’s significantly above July’s average of 14 such days.  Washington, D.C.’s record for highest number of 90 degree days in a calendar month is 25 back in July 2011.  By comparison, July 2000 was Washington, D.C.’s coolest July since 1918 with only one day in the 90s and a monthly average temperature of 74.7 degrees (combining daily high and low temperatures).

The average high temperature in Washington, D.C. for much of July is 89 degrees, so temperatures in the low to mid-90s aren’t significantly warmer than average.  Also, Washington, D.C. experienced its second longest streak of consecutive hours with temperatures at or above 80 degrees at 134 hours from July 23 – 28, 2016.  That’s a good example of the city’s “urban heat island effect” where urban areas tend to remain warmer overnight than surrounding, more rural suburbs.

Although several days this month have brought showers and thunderstorms, July 2016 will finish with slightly below average monthly precipitation.  National Airport has officially measured 3.13” of rain through July 30 compared to the monthly average of 3.73”.  NOAA’s outlook for August calls for near average temperatures and near average precipitation in the Mid-Atlantic Region.

Washington, D.C.’s Warmest July’s (Degrees Fahrenheit)

1.  2011 – 84.5

2.  2012 – 84.0

3.  2010, 1993 – 83.1

5.  1999 – 83.0

6.  2016 – 82.7

7.  1987 – 82.6

8.  1980 – 82.3

9.  1955 – 82.1

10.  1988– 81.9

11.  1994 – 81.8

Washington, D.C. 90 Degree Days in July (number of days at or above 90 degrees)

2016 – 23 (Third highest July total behind 2011, 1993 and 1987 - tied with July 1988)
2015 – 14
2014 – 9
2013 – 11
2012 – 22
2011 – 25 (Broke DC’s monthly record of 24 from July 1993 and July 1987)
2010 – 20
2009 – 7