A memorable June in the nation’s capital

 

A warm June day at the Avenel Pool in Potomac, Maryland

June 2025 will finish as DC’s first warmer and wetter than average June since 2021. Despite it’s near record-setting heat over its final week, June got off to a cool start. The drought conditions that DC languished in over much of the spring also came to an end this month.

The month got off to an unusually chilly start with a low of 48° at National Airport on June 1. It was DC’s coolest June temperature since 1972. The first 90-degree day of the year didn’t occur until June 12. That was DC’s latest first 90-degree day since 2003. 

The final third of June has been exceptionally warm and humid. DC’s first heat wave of the year occurred from June 22 – 26. Excessive heat warnings were in effect for three of those days as high temperatures approached the triple-digit mark. The hottest day was June 24 with high/low temperatures of 99°/79°. 

While June 2024 had one day of triple-digit heat, this June fell just short of reaching the century mark. The nation’s capital hasn’t had triple-digit June heat in consecutive years since 2010 – 2012. 

Father’s Day was unusually cool and wet in the nation’s capital. DC’s high of 72° on June 15 made it DC’s coolest Father’s Day since 2012. The 0.33” of rain on June 15 also made it DC’s wettest Father’s Day since 1999. Severe to extreme drought conditions had dominated weather headlines across the DMV (DC, Maryland, Virginia) through mid-May. However, a very wet second half of May combined with a rainy middle part of June helped bring an end to the drought conditions.

Rainfall occurred in the nation’s capital on seven consecutive days through June 19. Consequently, this month will finish with 5.48” of rain, well above DC’s June average of 4.20”.  The nation’s capital also has a rainfall surplus of 3.34” for the first six months of 2025 compared to a deficit of 0.64” for the equivalent period last year.

Hot summers without triple-digit heat?

 

A summer's day in Washington, D.C.

 

 

This week’s heat wave is the first of the year. While no triple-digit heat occurred, excessive heat warnings were in effect for the nation’s capital on three consecutive days as heat index or “feels-like” temperature approached 110°. Triple-digit heat is unusual in Washington, D.C. despite its frequency last year.

Washington, D.C. experienced triple-digit heat in three consecutive months last summer; June, July and August, for the first time since 2011. Before last year, no triple-digit heat occurred in the nation’s capital since 2016. Ironically, from 2016-2024 the nation’s capital had four summers that rank among DC’s Top 15 warmest. These summers featured some memorable heat waves, as described below.

2022: The hottest stretch of the summer was from July 18 – July 25.  DC’s average high/low temperatures during this eight-day heat wave were 93.25°/76.25°. Despite the hot and humid weather Washingtonians experienced, no record highs were set. The hottest temperature during this heat wave was 96° on July 23.

2021: The hottest week of this summer occurred from August 8 – August 14. This week-long heat wave saw average daily temperatures of 94.1°/72.9° in the nation’s capital. While DC’s hottest temperature during this period was 96° at National Airport, it was 100° at Dulles Airport on August 12. It’s sometimes more difficult for National Airport (DCA) to get as hot as downtown areas or inland areas since a south wind at DCA blows off the cooler waters of the Potomac River.

2020: The summer of 2020 ranks as the sixth warmest on record in the nation’s capital. There were two notable heat waves. A 20-day heat wave occurred from June 26 – July 15 when DC’s average high/low temperatures were 92°/73.8°. The hottest temperature during this 20-day period was 97° on July 3. A 7-day heat wave also occurred from July 17 – July 23. Although shorter, the heat was more intense with DC’s average daily high/low for this period being 96.4°/76.3°. It was 99° on both July 19 and July 20.

2019: A 12-day heat wave occurred from July 11 – July 22. DC’s average daily temperatures during this stretch were 93.75°/75.6°. The hottest temperature during this heat wave was 99° on July 21. There were unusually warm low temperatures at National Airport on July 20 (81°) and July 21 (80°).

Hottest summers in Washington, D.C. (Source: NOAA)

1. 81.3° - 2010
2. 81.1° - 2011
3. 80.9° - 2024
4. 80.5° - 2016
5. 80.4° - 2012
6. 80.2° - 2020
7. 80.0° - 1980
8. 79.6° - 2015
9. 79.5° - 2021, 2019
10. 79.4° - 2002, 1991
11. 79.3° - 2018, 1993
12. 79.2° - 2022, 1987
13. 79.1° - 1999, 1995, 1983
14. 79.0° - 1988
15. 78.9° - 2008, 1994, 1978, 1943