Feeling more like summer

 

An early fall day at the National Cathedral

Although September is the first month of meteorological fall (the three-month period of September, October and November), this September has gotten off to a very summery start in the nation’s capital. The DMV (DC, Maryland and Virginia) will continue to experience July-like heat much of this week.

More typically, September features some of the best weather of the year in the nation’s capital. Average daily high/low temperatures drop from 85°/69° on September 1 to 75°/59° by the end of the month. The amount of daylight continues to decline throughout September. Sunset will occur at 6:54 p.m. on September 30. The combination of reduced daylight and a lower sun angle contributes to the cooler average temperatures as September wears on. 

Five of DC’s 10 warmest September’s have occurred since 2005. DC’s hottest September temperature on record is 104° on September 7, 1881. Triple-digit September heat is a rarity in the nation’s capital and has occurred only four times since 1871, with none since 1980. To add to that, yesterday’s high temperature of 98° was DC’s hottest September temperature since September 7, 2023 (also 98°). By comparison, DC’s coolest September temperature is 36° from September 23, 1904.

Although Washington, D.C. averages 3.93” of September rainfall, the amount of rain can fluctuate wildly year-by-year. September can be a very wet month if decaying tropical systems bring appreciable rainfall. Such was the case with Floyd in 1999, Isabel in 2003 and Florence in 2018. This month can also be very dry in the nation’s capital. The driest September on record was in 2005 (0.11”) and the fourth driest occurred in 2019 (0.25”).

Last September featured near average temperatures and rainfall in the nation’s capital. By comparison, NOAA’s Climate Prediction Center expects this September to finish with warmer than average temperatures and near average rainfall.

The end of summer?

 

A late August day at the Avenel Park, Potomac, MD

The second half of August 2026 has felt more like September in the nation’s capital. This month will finish warmer than average. It will also become DC’s third wetter than average August in the last four years.

Following such a hot and humid June and July; that included four days of triple-digit heat, the stretches of cooler than average weather this month were welcome by residents of the DMV (DC, Maryland and Virginia). DC’s warmest temperature this month was 94°. High temperatures today could reach the low 90s and that would give Washingtonians 12 days of 90-degree heat. That’s right at DC’s average of between 10 and 11 days of 90-degree August heat over the last 30 years, according to NOAA data .

There has been a lot of fluctuation in August temperatures over the last decade. For example, the nation’s capital saw only five days in the 90s last August which was DC’s coolest since 2000. Meanwhile, a total of 20 days of 90-degree heat occurred in August 2016 when DC experienced its second hottest August on record. This August will finish almost a full degree warmer than average, giving DC residents the first warmer than average August since 2022. 

Unlike last August that finished as DC’s driest on record with only 0.2” of rain, this month has been wetter than average with 4.27” as of August 30. That’s welcome news for the DMV that has been mired in drought conditions for much of the year.

Although drought conditions have improved for much of the DMV over the course of the month, widespread areas of “abnormally dry” conditions still exist in the immediate DC Area, along with other areas of “moderate drought” conditions. The near record-setting heat on tap with highs in the mid to upper 90s for much of this week will exacerbate these dry conditions.

Recapping this summer’s weather

 

A summer evening at Nationals Park, Washington, D.C.

Despite several very hot days, this summer will conclude with near average seasonal temperatures and below average rainfall. Meteorological summer (June, July and August) ends on August 31.

August has been a relatively quiet weather month in the nation’s capital. The final third of the month has featured plenty of drier and cooler than average weather. Much of this week has felt more like early fall as many area students returned to school.

The hottest August temperature Washingtonians experienced was 94° on two days. Several days also had severe weather across the DMV (DC, Maryland and Virginia). That helped make this only the second wetter than average August in the nation’s capital during the last five years.

Last month featured some memorable weather in the nation’s capital. Not only did Washingtonians experience the hottest July 4 on record, but the Independence Day holiday was also the third consecutive day of triple-digit heat during an unusually extreme heat wave.

As hot as the first half of July 2026 was, the second half of the month felt more like early fall. The nation’s capital experienced only six warmer than average days between July 16 – July 31. July 2026 was also a drier than average month for the second consecutive year. That’s the longest such streak in more than a decade.

Drought conditions that dominated local weather headlines across the DMV for much of the spring worsened in June. The month was both warmer and drier than average in the nation’s capital. June 12 set a record high of 100°.

Having triple-digit heat in both June and July, but not August, made this the first such summer in the nation’s capital since 2010. This summer’s hottest temperature was 103° on July 4, while the coolest was 55° on June 2. DC’s rainiest day was August 2 with 1.74”.

Although this month will finish as a wetter than average month, it hasn’t been wet enough to offset how dry June and July were. Consequently, this will be DC’s third consecutive drier than average summer. However, it will finish with near average temperatures, despite the combined total of four days of triple-digit heat.