San Juan Island - Friday Harbor Weather Forecast

    • 56
    • 72

    Mostly Sunny

    • 57
    • 76

    Mostly Sunny

    • 59
    • 77

    Mostly Sunny

    • 56
    • 76

    Mostly Sunny

    • 53
    • 70

    Partly Sunny

    • 54
    • 68

    Mostly Cloudy

    • 53
    • 69

    Slight Chance Rain

Today 9 Aug San Juan County

Mostly sunny. Highs in the upper 60s to mid 70s. Light wind.

Tonight 9 Aug San Juan County

Mostly clear. Lows in the mid 50s to lower 60s. Light wind.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

San Juan Island - Friday Harbor Temperature Statistics

August Temperature

Friday Harbor Airport (1.9 miles)

  • Lowest 7 August, 2025

    50 °F

  • Average August

    60.1 °F

  • Highest 2 August, 2025

    71.1 °F

Climate (2020–Present)

Friday Harbor Airport (1.9 miles)

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

  • Average Low 2020–2025

    44.3 °F

  • Average 2020–2025

    51.7 °F

  • Average High 2020–2025

    59.5 °F
Get WillyWeather+ to remove ads