National Harbor Weather Forecast

    • 24
    • 50

    Becoming Sunny

    • 33
    • 42

    Chance Rain

    • 38
    • 53

    Mostly Cloudy

    • 36
    • 49

    Chance Rain

    • 45
    • 53

    Slight Chance Rain

    • 41
    • 62

    Mostly Cloudy

Today 21 Dec Arlington/Falls Church/Alexandria

Mostly sunny. Highs in the upper 40s. Northwest Winds 10 to 15 Mph with Gusts up to 25 Mph.

Tonight 21 Dec Arlington/Falls Church/Alexandria

Mostly clear. Lows in the mid 20s. Northwest Winds 5 to 10 Mph.

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  • Temperature Real-Time

National Harbor Temperature Statistics

December Temperature

Washington/Reagan National Airport, DC (4.3 miles)

  • Lowest 15 December, 2025

    18 °F

  • Average December

    34.8 °F

  • Highest 18 December, 2025

    57 °F

Climate (2020–Present)

Washington/Reagan National Airport, DC (4.3 miles)

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  • Average Low 2020–2025

    52.5 °F

  • Average 2020–2025

    60.4 °F

  • Average High 2020–2025

    69.1 °F
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