Lake Mercer Weather Forecast

    • 61
    • 71

    Mostly Cloudy

    • 60
    • 77

    Partly Sunny

    • 61
    • 81

    Mostly Sunny

    • 65
    • 84

    Mostly Sunny

    • 65
    • 87

    Slight Chance Rain Showers

    • 62
    • 72

    Chance Rain Showers

    • 57
    • 70

    Chance Rain Showers

Today 28 Sep Fairfax

Mostly cloudy. Highs around 70. Northwest Winds around 10 Mph.

Tonight 28 Sep Fairfax

Mostly cloudy. Lows around 60. Northwest Winds 5 to 10 Mph.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Mercer Temperature Statistics

September Temperature

Fort Belvoir (4.3 miles)

  • Lowest 25 September, 2026

    52 °F

  • Average September

    72.7 °F

  • Highest 1 September, 2026

    96.4 °F

Climate (2021–2026)

Fort Belvoir (4.3 miles)

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  • Average Low 2021–2026

    47.8 °F

  • Average 2021–2026

    58.2 °F

  • Average High 2021–2026

    68.3 °F
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