St Helena Weather Forecast

    • 62
    • 94

    Decreasing Clouds

    • 58
    • 84

    Mostly Sunny

    • 56
    • 86

    Mostly Sunny

    • 57
    • 90

    Mostly Sunny

    • 57
    • 91

    Mostly Sunny

    • 58
    • 92

    Mostly Sunny

Today 21 Jul North Bay Interior Valleys

Mostly cloudy in the morning then becoming partly cloudy. A slight chance of Showers. Highs in the upper 70s to mid 90s. Southwest Winds up to 5 Mph increasing to 10 to 15 Mph in the afternoon.

Tonight 21 Jul North Bay Interior Valleys

Mostly cloudy. Patchy fog. Lows in the 50s to lower 60s. West Winds up to 5 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

St Helena Temperature Statistics

July Temperature

Petaluma Municipal Airport (18 miles)

  • Lowest 17 July, 2026

    44.6 °F

  • Average July

    61.9 °F

  • Highest 13 July, 2026

    95 °F

Climate (2021–2026)

Petaluma Municipal Airport (18 miles)

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

  • Average Low 2021–2026

    44.8 °F

  • Average 2021–2026

    55.2 °F

  • Average High 2021–2026

    68.5 °F
Get WillyWeather+ to remove ads