Twentymile Lake Weather Forecast

    • 49
    • 69

    Mostly Sunny

    • 45
    • 72

    Chance Rain

    • 44
    • 63

    Partly Sunny

    • 39
    • 65

    Rain

    • 36
    • 45

    Rain Likely

    • 37
    • 54

    Mostly Sunny

    • 40
    • 59

    Mostly Sunny

Today 9 Sep Southern Clearwater Mountains

Mostly sunny. Patchy fog early in the morning. Highs 66 to 81.

Tonight 9 Sep Southern Clearwater Mountains

Mostly clear. Lows 38 to 53.

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  • Temperature Real-Time

Twentymile Lake Temperature Statistics

September Temperature

Grangeville - Idaho County Airport (24.9 miles)

  • Lowest 5 September, 2026

    41 °F

  • Average September

    54.8 °F

  • Highest 1 September, 2026

    82.4 °F

Climate (2021–2026)

Grangeville - Idaho County Airport (24.9 miles)

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  • Average Low 2021–2026

    37 °F

  • Average 2021–2026

    47.3 °F

  • Average High 2021–2026

    57.9 °F
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