How hot can June get?

 

A late-afternoon on a June day in Washington, D.C.

Although June has gotten off to a cooler than average start in the nation’s capital, there are often stretches of very hot June weather. Washingtonians experienced three June heat waves over the last 30 years that have lasted over a week. A "heat wave" is loosely defined as a minimum of three consecutive days of 90° heat or greater.

2024: An 11-day heat wave got underway on June 17. Four of the next 11 days had high temperatures of at least 95°. That includes June 22, 2024, when a high of 100° occurred in Washington, D.C. That was significant for being DC’s first June day of triple-digit heat in more than a decade since June 29, 2012 (104°). This heat wave helped June 2024 finish as DC’s second warmest on record.

2010:  The signature weather event of DC's warmest June was an 11-day heat wave from June 19 - 29. Seven of those 11 days had high temperatures of at least 95°, including a record high of 100° on June 24. That was also DC’s first instance of triple-digit June heat since 1997.

June 2010 was the first of three consecutive June’s with 100-degree heat. This June finished with 18 days of 90-degree heat compared to DC's June average of between seven and eight such days. As a result, June 2010 finished as the warmest on record in the nation’s capital.

1997: The first 17 days of June in 1997 were cooler than average in the nation's capital. That includes a June 3 record cool high of 58°, which is DC's average high on March 20. However, a major shift in the weather pattern occurred during the second half of the month. That led to a nine-day heat wave from June 20 – 28. The hottest day was June 25 that featured a record high of 100°.

Although nine of the final 13 days of this June were warmer than average, it still finished 3.2° cooler than average in the nation's capital. That helps underscore how a heat wave isn't always enough to offset cooler weather over the course of an entire month.