Does Hot Weather in June have any Special Significance?

Glen Echo, Maryland (June 2015)

Following the warmest May on record in the Nation’s Capital, the first half of June has also been warmer than average.  However, temperatures so far this month haven’t been as far above average as they were in May.  That said, the Mid-Atlantic Region is currently in the hottest stretch of weather to date of 2015.  Although no record highs were broken this week in the Nation’s Capital, some have been threatened. 

 

A “heat wave” is defined by meteorologists as a streak of at least three consecutive days with temperatures of 90 degrees or hotter.  Washingtonians experienced their first heat wave of the season from May 30 through June 1.  However, that was followed by four consecutive days of below average temperatures.  In fact, the high temperature on June 3 at National Airport (the official weather reporting site in the Nation’s Capital) was only 64 degrees which is the average high on April 7. 

Meanwhile, the pendulum has swung back the other way as today will be the 4^th consecutive day with temperatures in the 90s in the Mid-Atlantic Region.  Although some record high temperatures may be approached (particularly at Dulles Airport where weather records only go back to the 1960s), no record highs are likely to be broken the next few days.  The hottest temperature so far this year in the Nation’s Capital was 94 degrees on June 12.  That was Washington, D.C.’s hottest temperature since it was 95 degrees on September 6, 2014.

Some may wonder if a warmer than average May and June will translate to a warmer than average summer.   Although above average temperatures in May and June have on occasion served to foreshadow above average temperatures, that isn’t always the case.  For example, in a truly rare occurrence, June 2000 saw more 90 degree heat than July 2000 in the Nation’s Capital: five days compared to one day.  In fact, July 2000 saw nine days with high temperatures only in the 70s – more characteristic of May than July.  So a warm June doesn’t always correlate to a warmer than average summer.

National Weather Service data indicates that June 2010 was the warmest June on record in the Nation’s Capital.  That proved to be a harbinger of the rest of the summer as July 2010 finished tied for the third warmest on record in Washington, D.C., and above average temperatures continued in August and September 2010.  This illustrates that a warmer than average June can sometimes be a harbinger of what the entire summer may entail.

Meteorologists and climate scientists look at global weather patterns when issuing seasonal forecasts – such as the presence of El Nino – and the associated effects that occur around the world.  The U.S. Climate Prediction Center is expecting warmer than average temperatures to continue for the rest of June in the Mid-Atlantic Region.