Napa River - Napa Weather Forecast

    • 50
    • 71

    Decreasing Clouds

    • 55
    • 79

    Mostly Sunny

    • 56
    • 89

    Mostly Sunny

    • 56
    • 89

    Mostly Sunny

    • 56
    • 84

    Partly Sunny

    • 56
    • 85

    Mostly Sunny

Today 27 Sep North Bay Interior Valleys

Partly cloudy in the morning then becoming sunny. Patchy fog in the morning. Highs in the 60s to 70s. Southwest Winds 5 to 10 Mph increasing to 10 to 20 Mph in the afternoon.

Tonight 27 Sep North Bay Interior Valleys

Mostly clear in the evening then becoming partly cloudy. Patchy fog after midnight. Lows in the 40s to mid 50s. West Winds 5 to 15 Mph.

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Napa River - Napa Temperature Statistics

September Temperature

Napa, Napa County Airport (5.6 miles)

  • Lowest 6 September, 2026

    45.6 °F

  • Average September

    66 °F

  • Highest 9 September, 2026

    99.6 °F

Climate (2021–2026)

Napa, Napa County Airport (5.6 miles)

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  • Average Low 2021–2026

    47.3 °F

  • Average 2021–2026

    58.5 °F

  • Average High 2021–2026

    70.3 °F
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