Big Trinity Lake Weather Forecast

    • 45
    • 71

    Decreasing Clouds

    • 48
    • 73

    Mostly Sunny

    • 51
    • 77

    Partly Sunny

    • 50
    • 78

    Partly Sunny

    • 45
    • 70

    Partly Sunny

    • 45
    • 69

    Mostly Sunny

Today 18 Aug Boise Mountains

Partly cloudy. Highs 78 to 93.

Tonight 18 Aug Boise Mountains

Mostly clear. Patchy smoke after midnight. Lows 45 to 60.

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  • Temperature Real-Time

Big Trinity Lake Temperature Statistics

August Temperature

Boise Air Terminal (40.4 miles)

  • Lowest 3 August, 2026

    54.6 °F

  • Average August

    78.8 °F

  • Highest 1 August, 2026

    101.6 °F

Climate (2021–2026)

Boise Air Terminal (40.4 miles)

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  • Average Low 2021–2026

    44 °F

  • Average 2021–2026

    54.8 °F

  • Average High 2021–2026

    66.2 °F
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