San Juan Island - Friday Harbor Weather Forecast

    • 51
    • 68

    Rain Likely

    • 51
    • 68

    Partly Sunny

    • 50
    • 65

    Mostly Cloudy

    • 52
    • 66

    Mostly Cloudy

    • 51
    • 70

    Rain Likely

    • 50
    • 68

    Chance Rain

    • 49
    • 68

    Chance Rain

Today 28 Aug San Juan County

Partly sunny then becoming sunny early in the afternoon then becoming partly sunny. Highs in the 60s to lower 70s. South wind to 10 Mph increasing to 10 to 15 Mph in the afternoon.

Tonight 28 Aug San Juan County

Mostly cloudy. A chance of Showers and a slight chance of Thunderstorms after midnight. A chance of Showers in the morning. Lows in the upper 40s to mid 50s. Southwest wind 10 to 15 Mph becoming west after midnight.

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San Juan Island - Friday Harbor Temperature Statistics

August Temperature

Friday Harbor Airport (1.9 miles)

  • Lowest 3 August, 2026

    48.9 °F

  • Average August

    60.5 °F

  • Highest 25 August, 2026

    79 °F

Climate (2021–2026)

Friday Harbor Airport (1.9 miles)

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  • Average Low 2021–2026

    44.5 °F

  • Average 2021–2026

    51.9 °F

  • Average High 2021–2026

    59.7 °F
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