Granite State Park Weather Forecast

    • 41
    • 59

    Slight Chance Thunderstorms

    • 40
    • 60

    Partly Sunny

    • 38
    • 50

    Rain Showers Likely

    • 38
    • 54

    Chance Rain Showers

    • 39
    • 60

    Mostly Sunny

    • 39
    • 59

    Partly Sunny

Today 13 Sep Butte/Blackfoot Region

Mostly sunny in the Morning, then mostly cloudy with a 20 percent chance of Showers and Thunderstorms in the afternoon. Patchy fog in the morning. Highs in the upper 60s to mid 70s.

Tonight 13 Sep Butte/Blackfoot Region

Partly cloudy. Lows in the upper 30s to mid 40s.

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Granite State Park Temperature Statistics

September Temperature

Butte, Bert Mooney Airport (43.5 miles)

  • Lowest 5 September, 2025

    39.9 °F

  • Average September

    61.5 °F

  • Highest 3 September, 2025

    88 °F

Climate (2020–Present)

Butte, Bert Mooney Airport (43.5 miles)

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  • Average Low 2020–2025

    27.7 °F

  • Average 2020–2025

    41.7 °F

  • Average High 2020–2025

    55 °F
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