Roche Harbor Lake Weather Forecast

    • 53
    • 74

    Mostly Sunny

    • 52
    • 73

    Mostly Sunny

    • 52
    • 70

    Mostly Sunny

    • 52
    • 71

    Mostly Sunny

    • 52
    • 68

    Rain Likely

    • 51
    • 69

    Chance Rain

Today 16 Sep San Juan County

Sunny. Highs in the 70s. North wind to 10 Mph becoming east in the afternoon.

Tonight 16 Sep San Juan County

Clear. Lows in the 50s. Northeast wind to 10 Mph becoming south after midnight.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Roche Harbor Lake Temperature Statistics

September Temperature

Friday Harbor Airport (6.2 miles)

  • Lowest 10 September, 2025

    48 °F

  • Average September

    58 °F

  • Highest 3 September, 2025

    75.9 °F

Climate (2020–Present)

Friday Harbor Airport (6.2 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