Great Falls Weather Forecast

    • 62
    • 84

    Rain Showers Likely

    • 69
    • 87

    Mostly Sunny

    • 59
    • 88

    Rain Showers Likely

    • 53
    • 72

    Partly Sunny

    • 51
    • 72

    Partly Sunny

    • 53
    • 75

    Mostly Cloudy

Today 4 Sep Central and Southeast Montgomery

Sunny. A chance of Showers and Thunderstorms this afternoon. Highs in the mid 80s. South Winds 10 to 15 Mph. Chance of rain 50 percent.

Tonight 4 Sep Central and Southeast Montgomery

Mostly cloudy with a chance of Showers and Thunderstorms in the Evening, then partly cloudy after midnight. Lows in the lower 60s. Southwest Winds 5 to 10 Mph. Chance of rain 50 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Great Falls Temperature Statistics

September Temperature

Washington/Dulles International Airport, DC (9.3 miles)

  • Lowest 1 September, 2025

    50 °F

  • Average September

    66.2 °F

  • Highest 1 September, 2025

    80.1 °F

Climate (2020–Present)

Washington/Dulles International Airport, DC (9.3 miles)

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  • Average Low 2020–2025

    47.8 °F

  • Average 2020–2025

    58.2 °F

  • Average High 2020–2025

    68.5 °F
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