Arnold Weather Forecast

    • 55
    • 88

    Chance Rain Showers

    • 52
    • 82

    Chance Rain Showers

    • 50
    • 81

    Partly Sunny

    • 52
    • 84

    Sunny

    • 56
    • 90

    Mostly Sunny

    • 52
    • 83

    Chance Rain

Today 18 Sep Northwestern Mendocino Interior

Mostly cloudy. Slight chance of rain in the afternoon. Highs 83 to 98.

Tonight 18 Sep Northwestern Mendocino Interior

Mostly cloudy. Slight chance of Showers and Thunderstorms. Lows 53 to 63.

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Arnold Temperature Statistics

September Temperature

Ukiah Municipal Airport (28.6 miles)

  • Lowest 7 September, 2025

    50 °F

  • Average September

    69.6 °F

  • Highest 2 September, 2025

    102.9 °F

Climate (2020–Present)

Ukiah Municipal Airport (28.6 miles)

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  • Average Low 2020–2025

    46.8 °F

  • Average 2020–2025

    60.7 °F

  • Average High 2020–2025

    76.3 °F
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