Great South Bay Weather Forecast

    • 69
    • 77

    Chance Rain Showers

    • 70
    • 79

    Mostly Sunny

    • 71
    • 78

    Mostly Sunny

    • 76
    • 83

    Mostly Sunny

    • 74
    • 83

    Partly Sunny

    • 74
    • 82

    Partly Sunny

Today 11 Jul Southwest Suffolk

Patchy fog this morning. Mostly cloudy with a chance of Showers this Morning, then partly sunny with a chance of Showers with a slight chance of Thunderstorms this afternoon. Highs in the lower 80s. East Winds 5 to 10 Mph. Gusts up to 20 Mph this afternoon. Chance of rain 50 percent.

Tonight 11 Jul Southwest Suffolk

Mostly cloudy with a chance of Showers in the Evening, then mostly clear after midnight. Lows in the mid 60s. Northeast Winds 5 to 10 Mph. Chance of rain 30 percent.

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Great South Bay Temperature Statistics

July Temperature

Islip, Long Island Mac Arthur Airport (8.1 miles)

  • Lowest 8 July, 2026

    63 °F
  • Average July

    76.9 °F
  • Highest 3 July, 2026

    98.7 °F

Climate (2021–2026)

Islip, Long Island Mac Arthur Airport (8.1 miles)

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  • Average Low 2021–2026

    47.3 °F
  • Average 2021–2026

    55.2 °F
  • Average High 2021–2026

    63.1 °F
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