Great Falls Weather Forecast

    • 57
    • 73

    Decreasing Clouds

    • 61
    • 80

    Partly Sunny

    • 62
    • 84

    Mostly Sunny

    • 62
    • 86

    Mostly Cloudy

    • 59
    • 72

    Rain Showers Likely

    • 54
    • 68

    Rain Showers Likely

Today 29 Sep Central and Southeast Montgomery

Mostly cloudy. Highs in the lower 70s. Northwest Winds around 5 Mph.

Tonight 29 Sep Central and Southeast Montgomery

Partly cloudy. Patchy fog after midnight. Lows in the upper 50s. Light and variable Winds.

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Great Falls Temperature Statistics

September Temperature

Washington/Dulles International Airport, DC (9.3 miles)

  • Lowest 24 September, 2026

    50.6 °F

  • Average September

    72.3 °F

  • Highest 1 September, 2026

    94.6 °F

Climate (2021–2026)

Washington/Dulles International Airport, DC (9.3 miles)

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  • Average Low 2021–2026

    47.6 °F

  • Average 2021–2026

    58.3 °F

  • Average High 2021–2026

    68.6 °F
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