Great South Bay Weather Forecast

    • 70
    • 73

    Increasing Clouds

    • 71
    • 75

    Mostly Cloudy

    • 63
    • 77

    Partly Sunny

    • 64
    • 68

    Mostly Cloudy

    • 66
    • 72

    Chance Rain Showers

    • 65
    • 71

    Chance Rain Showers

Today 16 Sep Southwest Suffolk

Mostly sunny. Highs in the mid 70s. Southwest Winds 5 to 10 Mph.

Tonight 16 Sep Southwest Suffolk

Mostly cloudy in the Evening, then becoming partly cloudy. Lows in the mid 60s. Southwest Winds 5 to 10 Mph.

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  • Temperature Real-Time

Great South Bay Temperature Statistics

September Temperature

Islip, Long Island Mac Arthur Airport (8.1 miles)

  • Lowest 7 September, 2026

    56.6 °F

  • Average September

    72.3 °F

  • Highest 10 September, 2026

    86.6 °F

Climate (2021–2026)

Islip, Long Island Mac Arthur Airport (8.1 miles)

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  • Average Low 2021–2026

    47.2 °F

  • Average 2021–2026

    55.2 °F

  • Average High 2021–2026

    63.1 °F
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