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.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our National Harbor's climate page.

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).

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

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our National Harbor's climate page.

More climate data for National Harbor

Temperature Rainfall Sunshine Humidity Wind Speed

See the full National Harbor climate overview or explore weather in the United States of America.