Historic Territory

Great Falls, Maryland

No measureable rainfall has occurred in the Nation’s Capital through June 15.  That ties this month with 1967 and 1976 for driest first half of June on record.  Weather records in Washington, D.C. date back to 1871, so that’s an especially impressive feat.  

There have been several days this month with scattered showers and thunderstorms in the Mid-Atlantic Region, but no widespread precipitation.  The combination of several hotter than average days and less rainfall makes the wetter than average May seem distant.  This month’s rainfall deficit is nearing 2”.  

Longtime residents know June can be a very wet month in the Nation’s Capital.  Three of the five wettest Junes on record in Washington, D.C. occurred since 2003.  Just two years ago, Washingtonians saw 11.94” of rain officially measured at National Airport.  There were 18 days with measureable rainfall in Washington, D.C. during June 2015.

June can be both a hot month and a wet month as was the case in 2015.  That’s when a total of 12 days reached or exceeded 90° and contributed to making the month nearly 3° warmer than average.  The Nation’s Capital has averaged between 7 and 8 days in the 90s during the month of June since 1993.  This month has already had 6 days in the 90s, with the likelihood of adding to that total during the Father’s Day weekend.  Meanwhile, June’s weather doesn’t necessarily correlate to what the rest of the summer will be like.  

The first “heat wave” of 2017 occurred earlier this month when temperatures climbed into the 90s for four consecutive days from June 11 through June 14.  While some record highs were tied or broken, this week’s heat wave doesn’t rank among the historic June heat waves in this part of the country.  For example, a 14 day streak of 90° occurred in June 1994, and in June 2010, there was an 11 day heat wave.  Moreover, that 11 day heat wave largely contributed to making June 2010 the hottest on record in the Nation’s Capital.

The 14-day heat wave in June 1994 included a record high of 101° on June 15 in Washington, D.C.  By comparison, there were only 5 days in the 90s last June.  NOAA’s outlook for the rest of June is for an above average potential for warmer and wetter than average conditions in the Mid-Atlantic Region.