San Juan Island - Roche Harbor Weather Forecast

    • 55
    • 70

    Gradual Clearing

    • 55
    • 70

    Partly Sunny

    • 56
    • 71

    Mostly Cloudy

    • 57
    • 73

    Partly Sunny

    • 58
    • 75

    Mostly Sunny

    • 57
    • 76

    Mostly Sunny

Today 18 Jul San Juan County

Mostly sunny then becoming mostly cloudy early in the afternoon then becoming mostly sunny. Highs in the mid 60s to lower 70s. Light wind becoming south around 10 Mph in the afternoon.

Tonight 18 Jul San Juan County

Partly cloudy. Lows in the 50s. Southwest wind 10 to 15 Mph.

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San Juan Island - Roche Harbor Temperature Statistics

July Temperature

Friday Harbor Airport (8.1 miles)

  • Lowest 4 July, 2025

    46.7 °F

  • Average July

    61.4 °F

  • Highest 15 July, 2025

    87.1 °F

Climate (2020–Present)

Friday Harbor Airport (8.1 miles)

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  • Average Low 2020–2025

    44.3 °F

  • Average 2020–2025

    51.7 °F

  • Average High 2020–2025

    59.5 °F
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