South Mountain Reservoir Weather Forecast

    • 42
    • 75

    Mostly Sunny

    • 42
    • 75

    Mostly Sunny

    • 41
    • 73

    Mostly Sunny

    • 44
    • 76

    Mostly Sunny

    • 45
    • 79

    Mostly Sunny

    • 46
    • 80

    Mostly Sunny

    • 46
    • 81

    Mostly Sunny

Today 6 May Modoc County

Sunny. Highs in the lower 70s to lower 80s. Light Winds becoming south around 5 Mph late this Morning, then shifting to the west this afternoon.

Tonight 6 May Modoc County

Mostly clear. Lows in the lower to mid 40s. West Winds 10 to 15 Mph decreasing to around 5 Mph well after midnight.

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South Mountain Reservoir Temperature Statistics

May Temperature

Alturas (22.4 miles)

  • Lowest 1 May, 2026

    30.7 °F

  • Average May

    56.7 °F

  • Highest 4 May, 2026

    75.9 °F

Climate (2021–Present)

Alturas (22.4 miles)

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  • Average Low 2021–2026

    33.5 °F

  • Average 2021–2026

    49.6 °F

  • Average High 2021–2026

    64.9 °F
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