San Clemente Island - Northwest Harbor Weather Forecast

    • 58
    • 67

    Partly Sunny

    • 57
    • 65

    Partly Sunny

    • 57
    • 65

    Mostly Cloudy

    • 57
    • 65

    Patchy Fog

    • 56
    • 64

    Cloudy

    • 57
    • 65

    Rain Showers Likely

Today 18 Dec Catalina and Santa Barbara Islands

Partly cloudy. Highs in the upper 60s to mid 70s.

Tonight 18 Dec Catalina and Santa Barbara Islands

Mostly clear. Lows in the mid to upper 50s.

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San Clemente Island - Northwest Harbor Temperature Statistics

December Temperature

San Clemente Island NALF (0.6 miles)

  • Lowest 2 December, 2025

    50 °F

  • Average December

    62 °F

  • Highest 9 December, 2025

    70 °F

Climate (2020–Present)

San Clemente Island NALF (0.6 miles)

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  • Average Low 2020–2025

    56.9 °F

  • Average 2020–2025

    61.3 °F

  • Average High 2020–2025

    66 °F
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