Great South Bay Weather Forecast

    • 57
    • 65

    Increasing Clouds

    • 53
    • 64

    Mostly Sunny

    • 55
    • 64

    Mostly Sunny

    • 57
    • 65

    Slight Chance Rain Showers

    • 60
    • 68

    Partly Sunny

    • 63
    • 71

    Partly Sunny

Today 31 May Southwest Suffolk

Partly sunny. Highs in the lower 70s. Southwest Winds 10 to 15 Mph.

Tonight 31 May Southwest Suffolk

Partly cloudy in the Evening, then mostly cloudy with a slight chance of Showers after midnight. Lows in the mid 50s. West Winds 5 to 10 Mph with Gusts up to 20 Mph, becoming north after midnight. Chance of rain 20 percent.

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Great South Bay Temperature Statistics

May Temperature

Islip, Long Island Mac Arthur Airport (8.1 miles)

  • Lowest 1 May, 2026

    40.6 °F

  • Average May

    61 °F

  • Highest 20 May, 2026

    93.7 °F

Climate (2021–Present)

Islip, Long Island Mac Arthur Airport (8.1 miles)

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  • Average Low 2021–2026

    47.3 °F

  • Average 2021–2026

    55.1 °F

  • Average High 2021–2026

    63 °F
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