San Juan Island - Grandmas Cove Weather Forecast

    • 56
    • 78

    Patchy Smoke

    • 57
    • 81

    Mostly Sunny

    • 54
    • 77

    Partly Sunny

    • 53
    • 73

    Partly Sunny

    • 52
    • 64

    Mostly Cloudy

    • 52
    • 63

    Mostly Cloudy

    • 51
    • 63

    Mostly Cloudy

Today 21 Jul San Juan County

Mostly sunny. Patchy smoke. Highs in the upper 70s to mid 80s. Light wind.

Tonight 21 Jul San Juan County

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

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  • Temperature Real-Time

San Juan Island - Grandmas Cove Temperature Statistics

July Temperature

Friday Harbor Airport (3.7 miles)

  • Lowest 5 July, 2026

    46.9 °F

  • Average July

    58.9 °F

  • Highest 14 July, 2026

    78.1 °F

Climate (2021–2026)

Friday Harbor Airport (3.7 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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