National Harbor
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National Harbor Weather in August

National Harbor in August sees very high temperatures, with highs around 31°C (88°F) and overnight lows of 20°C (68°F). Rainfall is fairly high at around 94 mm (3.7 in) on average, so pack waterproofs just in case.

Rainfall in National Harbor in August

Typically, about 10 days will experience rainfall, with an average of 94 mm (3.7 in) for the month. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in National Harbor in August

Daytime temperatures in National Harbor reach 31°C (88°F) in August, dropping to 20°C (68°F) at night. It's usually most comfortable outside during the morning and later in the day. Nights remain mild at 20°C (68°F), making evenings a pleasant time to be outdoors.

Sunshine in National Harbor in August

There are approximately 262 hours of sunshine this month, resulting in mostly clear days.

Wind Speed in National Harbor in August

August sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.

For National Harbor itself, April generally stands out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

National Harbor Temperature in August

Min Temperature
20°C (68°F)
Max Temperature
31°C (88°F)
Chance of Rain
34%
Precipitation
94 mm (3.7 in)
Rainy days
10 days
Humidity
69% *
Windspeed
4 m/s (8 knots) *
Sunshine
262 hours *
Percentage Sunshine
62% *
* Data from: Washington DC, the United States of America (7 KM, 4 Miles).

National Harbor Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in National Harbor - and find the best time to visit.

Best Places in the United States of America in August

Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in August →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

What to Wear in National Harbor in August

Warm weather calls for comfortable, breathable clothing in August. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in National Harbor in August

We rated the following activities from 1 (least suitable) to 10 (best) to do.

  • Swimming
    9/10
  • Cycling
    7/10
  • Walking
    7/10
  • Camping
    8/10
  • Outdoor sports
    7/10

National Harbor 3-Day Forecast

Popular in August

Where to go in August - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.