That's a wrap on August

 

August 2024 has been a memorable weather month in the nation's capital.  It has featured multiple weather extremes, including record heat and record rainfall, as well as the coolest weather in decades. It will also finish as a wetter than average August with near average temperatures.

The month got off to a very hot start with above average temperatures on nine of the first 10 days.  However, there was a hard pivot to cooler than average temperatures between August 11 - August 25.  That included lows in the 50s on August 21 - August 22 for the first time since 2004.  Dulles Airport was even cooler with a record low of 49° on August 22.  Dulles hadn't been in the 40s during the month of August, prior to this, since 1998.

The final week of August saw a major swing back to extreme heat.  The four-day stretch from August 26 - 29 was as hot as any late-season heat wave of recent memory. DC had a record high of 101° on August 28.  Not only was that a record high for the date, but it was DC's first instance of triple-digit heat in August since 2016.  It was also DC's hottest temperature this late in the season since September 2, 1980 (also 101°).

The large swing in temperatures, from hot to cool to very hot, will produce near average temperatures for the entire month.  August 2024 will finish as DC's third warmest month of the year, behind both June and July. That's notable since August is normally DC's second warmest month of the year.  However, June 2024 was unusually warm and finished as DC's second warmest on record.  Thus, August will finish with an average temperature of 79.3°, compared to 79.7° in June.

August has also been a wet month in the nation's capital. It was largely due to the remnants of Tropical Storm Debby after its August 8 landfall in South Carolina.  A total of 3.31" of rain was recorded at National Airport from August 8 - August 10, which was more than half of DC's monthly total of 4.58".  Meanwhile, Dulles Airport saw 1.64" from Debby's remnants for a sizeable percentage of its monthly rainfall total of 4.99".

Extreme late-season heat in the DMV

 

This summer is one of the hottest in recent memory with multiple days of triple-digit heat. Perhaps it comes as no surprise, then, that temperatures today will approach the century mark. Check out this story I wrote for the WUSA9 website for details.

Enjoying August's cool-down

 

A fall-like August day in suburban Washington, D.C.

Washingtonians have enjoyed some of the coolest August weather in decades over the last week. The cooler than average weather has been particularly welcome given how hot June and July were in the nation's capital. 

June finished as DC's second warmest on record, while July was DC's fourth hottest. Nine of the first 10 days of August were also warmer than average, including an August 2 high of 99° at National Airport and a record high of 101° at Dulles Airport.

However, once the remnants of Tropical Storm Debby exited the DMV on August 11, there has been a major shift in the local weather pattern. Since then, 11 days have been cooler than average. Not since late-March has the nation's capital experienced a similar stretch of below average temperatures.

Moreover, temperatures over the last several days have felt more like late-September than August. Washington, D.C. experienced its first August temperatures in the 50s since 2004 with lows of 59° and 58°, respectively, at National Airport on August 21 and August 22. In addition, DC's high temperatures on August 21 and 22 were only 76° and 78°. Washingtonians haven't experienced consecutive daily high temperatures in the 70s during August since 2017.

Meanwhile, Dulles Airport was even cooler with a record low of 49° on August 22. That was its first August temperature in the 40s since August 20, 1998 (47°). National Airport also had a comfortable low temperature of 57° on August 20, 1998. Those comfortable temperatures were followed by an unusual late-August heat wave with highs in the 90s.

That's similar to what my colleagues and I on the WUSA9 Weather Team are expecting over the final week of this month. Highs this week will rebound to the low to mid-90s and that's above average for late-August. Although DC's average monthly temperature (combining daily high/low temperatures) is below average through August 24, this week's weather should help it finish near or slightly above average.