National Harbor Weather in December

December in National Harbor brings low temperatures, with daytime highs of 10°C (50°F) and nights around 1°C (34°F). Quite a bit of rainfall is expected, around 101 mm (4 in), so pack an umbrella.

Rainfall in National Harbor in December

Typically, you can expect about 11 days of rain this month, with 101 mm (4 in) on average. When showers do arrive, they tend to be on the heavier side. Worth being prepared even if rain days are not that numerous.

Temperature in National Harbor in December

December in National Harbor brings low temperatures, with highs of 10°C (50°F) and nights around 1°C (34°F). The month of December belongs to the winter season. Expect a cold feel throughout the day, not just in the mornings and evenings. Warm layers are essential. Nights drop to 1°C (34°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.

Sunshine in National Harbor in December

With about 130 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.

Wind Speed in National Harbor in December

Wind speeds average 4 m/s (8 knots) during December. At this speed, expect moderate winds that can raise dust and move small branches. Since this is an average, some days have gentle light winds while others experience stronger breezes that are quite noticeable.

December in National Harbor can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.