National Harbor
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National Harbor Weather in May

With daytime temperatures of 24°C (75°F) and nighttime lows of 14°C (57°F), May in National Harbor brings high temperatures during the day. Do keep in mind that quite a bit of rainfall is typical. Around 111 mm (4.4 in) falls on average.

Rainfall in National Harbor in May

Past climate data indicates that roughly 12 days will see rain, totalling around 111 mm (4.4 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 May

In May, National Harbor gets high temperatures, with highs of 24°C (75°F). Nights cool to around 14°C (57°F). This kind of day-to-night contrast is typical for this time of year. Nights cool down to 14°C (57°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in National Harbor in May

Expect a lot of sunshine this month, with about 259 hours of sun. These sunny conditions add to the overall experience.

Wind Speed in National Harbor in May

May 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 May

Min Temperature
14°C (57°F)
Max Temperature
24°C (75°F)
Chance of Rain
40%
Precipitation
111 mm (4.4 in)
Rainy days
12 days
Humidity
64% *
Windspeed
4 m/s (8 knots) *
Sunshine
259 hours *
Percentage Sunshine
59% *
* 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 May

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 May →

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 May

Pleasant temperatures in May mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. 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 May

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

  • Swimming
    9/10
  • Cycling
    9/10
  • Walking
    9/10
  • Camping
    6/10
  • Outdoor sports
    9/10

National Harbor 3-Day Forecast

Popular in May

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

Bucket list

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