South Mountain Reservoir Weather Forecast

    • 33
    • 56

    Increasing Clouds

    • 39
    • 54

    Chance Rain

    • 39
    • 52

    Rain

    • 35
    • 46

    Rain/Snow

    • 36
    • 49

    Rain/Snow

    • 35
    • 48

    Rain

    • 31
    • 44

    Chance Rain

Today 14 Dec Modoc County

Sunny. Highs in the mid 50s to lower 60s. South Winds 5 to 10 Mph.

Tonight 14 Dec Modoc County

Partly cloudy until well after midnight then becoming mostly cloudy. Lows in the lower 30s to lower 40s. South Winds 5 to 10 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

South Mountain Reservoir Temperature Statistics

December Temperature

Alturas (22.4 miles)

  • Lowest 1 December, 2025

    15.1 °F

  • Average December

    41.7 °F

  • Highest 10 December, 2025

    64 °F

Climate (2020–Present)

Alturas (22.4 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2020–2025

    33.3 °F

  • Average 2020–2025

    49.3 °F

  • Average High 2020–2025

    64.4 °F
Get WillyWeather+ to remove ads