Notable June Heat Waves

Lake Needwood, Derwood, Maryland

While typically not as hot as July or August, the month of June has had some memorable heat waves in the Nation’s Capital.  Five of DC’s 10 warmest Junes have occurred just since 2010.  June 1994 was DC’s warmest on record until 2010 and remains the second warmest.  Washingtonians haven’t had a cooler than average June in more than a decade since 2009.

2019: Although last June didn’t rank among DC’s 10 warmest, it finished on a hot note with a six-day heat wave.  The hottest day during that six-day stretch was June 29 with high/low temperatures of 96°/72°.  That wasn’t close, however, to DC’s record high for the date of 104°.  A “heat wave” is three or more consecutive days with highs of at least 90°.

2011: DC’s fourth warmest June was noteworthy for several reasons.  The longest heat wave of the month was also six-days long, but occurred much earlier (June 7 – 12) and included two record highs:  99° on June 8 and 102° on June 9.  The June 9 temperature of 102° tied the existing record.

2010: DC’s warmest June on record with 18 days of 90° heat that included an 11-day heat wave from June 19 – 29.  Six of those 18 days had high temperatures of 95°/+.  DC residents had a record high of 100° on June 24.  That was also DC’s first instance of triple-digit June heat since 1997.  The fact more than a decade passed since the previous time Washingtonians experienced 100° underscores how unusual it was to see such heat in three consecutive June’s through 2012.

1997: This was an unusual June since it got off to a very cool start.  The June 3 high temperature of 58° set a new record for DC’s coolest high temperature for the date.  There was a major shift in the weather pattern during the second half of the month, with a nine-day heat wave from June 20 – 28.  The hottest day was June 25 that featured a record high of 100°.  Despite the impressive heat during the final third of the month, June 1997 was still a cooler than average month.

1994: For nearly two decades, June 1994 held the distinction of DC’s hottest on record.  It also featured the longest heat wave of the summer with a 14-day heat wave from June 13 – 26.  The hottest day was June 15 with a record high temperature of 101°.  A total of five record highs were set during the month, including three consecutive records from June 14 – 16 that still stand today.  No June has had more than one day of 100° heat in the Nation’s Capital.