How Does June 2015 Compare to Average?

Suburban Washington, D.C.   (June 2015)

June 2015 is now the second wettest June on record in the Nation’s Capital with a monthly total of 11.94”.  This month will also finish as the sixth warmest June on record in Washington, D.C., with an average temperature of 78.1 degrees (combining daily high and low temperatures).  That’s following the warmest May on record in the Nation’s Capital that saw less than half its monthly average amount of rain.

June has featured twelve days with temperatures in the 90s, including two separate heat waves.  Meteorologists define a “heat wave” as any period of at least three consecutive days with high temperatures of 90 degrees or greater.  The first heat wave occurred from June 11 – 16 and the second occurred from June 20 – 23.  This month’s hottest temperature was 96 degrees and occurred twice (on June 16 and June 23). 

This June has had seven days with widespread severe weather across the Mid-Atlantic Region.  In addition, on two separate occasions there were daily rainfall records set at National Airport (the official weather reporting site for Washington, D.C.).  On June 20, 2.37” of rain fell downtown in conjunction with multiple severe weather reports across the DC Metro Region.  This past Saturday, June 27, another 2.75” occurred at National Airport, while two EF-1 tornadoes touched down in Charles and St. Mary’s Counties in southern Maryland.  Although these tornadoes caused some damage, fortunately there were no fatalities.

The dramatic shift from being significantly drier than average in May to being the second wettest June on record illustrates the high degree of variability in weather patterns from one month to the next.  Despite the ample heat and prodigious rainfall that’s occurred this June, the month is ending with more comfortable weather.  High temperatures today in the Nation’s Capital were in the low to mid 80s – including 84 degrees downtown – slightly below the daily average of 88 degrees.  

Ironically, that’s a far cry from three years ago today when Washington, D.C. saw its hottest June day on record at 104 degrees.

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

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

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Top Six Warmest June’s in Washington, D.C. (at National Airport)

1.  80.6°   (2010)
2.  79.4°   (1994)
3.  79.2°   (1943)
4.  78.8°   (2011)
5.  78.7°   (1981)
6.  78.1°   (2015)

Just How Warm and Wet has June Been in the Nation's Capital?

Severe Weather Reports from NOAA   (June 20, 2015)

June is continuing last month’s trend of being warmer than average in the Nation’s Capital.  However, unlike May, this month is poised to finish as one of the wettest on record.  Through June 25, Washington, D.C. has officially seen 9.18” of rain as measured at National Airport.  That’s more than double the monthly average of 3.78” according to the National Weather Service and would qualify this month as the fifth wettest June on record. 

Although no record highs have been set, 12 of the first 23 days of this month were significantly warmer than average with highs in the 90s.  In fact, daily high temperatures reached 96 degrees on two different days this month, making for the hottest weather since last August.  Through June 25, this has been the sixth warmest June on record in the Nation’s Capital.

It’s interesting to note that three of the wettest Junes on record in the Nation’s Capital (including this month) have occurred during the last 15 years.   The wettest June on record came in 2006 with a total of 14.02” at National Airport.  Since Washington, D.C. averages only 39.74” in a given year, getting more than a third of that in a single month is astonishing.  More recently nearly 10” of rain fell in the Nation’s Capital during the month of June 2013. 

Unfortunately, much of the rain that’s come this month has been associated with severe weather.  In just the last week, there have been three days with severe weather in the Mid-Atlantic Region.  For example, on June 20 the remnants of Tropical Storm Bill enhanced the rainfall that a cold front brought the Mid-Atlantic Region.  This cold front brought a significant amount of severe weather reported locally in addition to the daily rainfall record of 2.37” that was set at National Airport last Saturday.      

Although the 2006 record of 14.02” should be safe as D.C.’s wettest June, only another 2.36” needs to fall before the end of the month to make this the second wettest June on record.  Flood watches have already been issued across the Mid-Atlantic Region for more significant rain tomorrow and tomorrow night.

The Top Five Wettest June’s in the Nation’s Capital

1.  14.02”  (2006)
2.  11.53”  (1972)
3.  10.94”  (1900)
4.  9.97”    (2013)
5.  9.18”    (Through June 25, 2015)