Guerneville Weather Forecast

    • 55
    • 77

    Mostly Cloudy

    • 52
    • 77

    Mostly Cloudy

    • 54
    • 81

    Mostly Sunny

    • 53
    • 80

    Partly Sunny

    • 52
    • 73

    Areas Fog

    • 53
    • 75

    Patchy Fog

Today 20 Aug North Bay Interior Valleys

Mostly cloudy in the morning then becoming partly cloudy. Patchy fog in the morning. Highs in the lower 70s to mid 80s. Southwest Winds 5 to 15 Mph.

Tonight 20 Aug North Bay Interior Valleys

Mostly cloudy. Patchy fog. Lows in the 50s. Southwest Winds 10 to 15 Mph.

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Guerneville Temperature Statistics

August Temperature

Santa Rosa, Santa Rosa Sonoma County Airport (9.3 miles)

  • Lowest 10 August, 2026

    49.6 °F

  • Average August

    69 °F

  • Highest 1 August, 2026

    98.7 °F

Climate (2021–2026)

Santa Rosa, Santa Rosa Sonoma County Airport (9.3 miles)

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  • Average Low 2021–2026

    45.9 °F

  • Average 2021–2026

    58.6 °F

  • Average High 2021–2026

    72.8 °F
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