Does June’s Weather Predict the Rest of Summer ?

June is Washington, D.C.’s third hottest month of the year.  Area residents know there have been some significant June heat waves in recent decades, as well as some exceptionally wet weather.  However, June’s weather isn’t always a good harbinger of what the entire summer’s weather will be like.

One case in point occurred in June 1994.  Washingtonians experienced a 14-day heat wave with temperatures of at least 90° from June 13 – June 26.  The hottest day was the June 15^th record high of 101° that remains tied for third highest June temperature on record in the Nation’s Capital.  The month finished with an average temperature of 79.4°; significantly higher than DC’s June average of 75.2°.

The summer of 2016 was also interesting for DC residents in that the spring and first third of June were somewhat cool.  DC didn’t experience its first 90° day that year until June 11, several weeks after the average first 90° temperature normally occurs around May 18.  However, despite the relatively late first 90° of 2016, DC reached 100° on July 25, 2016 and on three more days the following month.  July and August 2016 each rank among the warmest on record in the Nation’s Capital.

The Nation’s Capital has experienced three of its five wettest Junes on record since 2006.  However, a wet or dry June isn’t a strong indicator of what might occur in July and August.  For example, Washington, D.C. had 14.02” in its wettest June on record in 2006, but was followed by below average July and August rainfall.  On the other hand, the month of June 2017 was DC’s third driest on record, but was followed by wetter than average conditions in July and August. 

While NOAA expects near average temperatures and rainfall this month, the Mid-Atlantic Region should expect a warmer and wetter than average summer, overall, based on NOAA’s three month outlook.

Washington, D.C.’s Five Warmest June’s (Source: National Weather Service)

1.  80.6° (2010)
2.  79.4° (1994)
3.  79.2° (1943)
4.  78.8° (2011)
5.  78.7° (1981)

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DC’s Five Coolest June’s

1.  65.9° (1907)
2.  67.0° (1903)
3.  68.6° (1927)
4.  69.1° (1926, 1878)

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DC’s Wettest June’s

1.  14.02” (2006)
2.  11.94” (2015)
3.  11.53” (1972)
4.  10.94” (1900)
5.  9.97” (2013)

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DC’s Driest June’s

0.86” (1940)
0.95” (1988)
1.13” (2017)
1.21” (1976)
1.24” (1954, 1894)