Flat Island Weather Forecast

    • 51
    • 57

    Mostly Sunny

    • 50
    • 55

    Chance Rain Showers

    • 46
    • 57

    Partly Sunny

    • 47
    • 56

    Partly Sunny

    • 46
    • 56

    Mostly Sunny

    • 48
    • 55

    Partly Sunny

Today 19 Sep Coastal Washington

Sunny. Highs in the lower 60s. Northwest Winds 5 to 10 Mph with Gusts up to 20 Mph.

Tonight 19 Sep Coastal Washington

Clear in the Evening, then becoming partly cloudy. Lows in the mid 40s. North Winds around 5 Mph in the Evening, becoming light and variable.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Flat Island Temperature Statistics

September Temperature

Bar Harbor, Hancock County-Bar Harbor Airport (32.3 miles)

  • Lowest 9 September, 2026

    44.1 °F

  • Average September

    60.5 °F

  • Highest 10 September, 2026

    80.1 °F

Climate (2021–2026)

Bar Harbor, Hancock County-Bar Harbor Airport (32.3 miles)

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  • Average Low 2021–2026

    38.2 °F

  • Average 2021–2026

    46.5 °F

  • Average High 2021–2026

    54.6 °F
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