Port Jefferson Weather Forecast

    • 60
    • 63

    Rain

    • 64
    • 67

    Rain

    • 61
    • 67

    Rain Showers

    • 61
    • 70

    Mostly Cloudy

    • 63
    • 72

    Partly Sunny

    • 64
    • 73

    Partly Sunny

    • 62
    • 73

    Chance Rain Showers

Today 26 Sep Northwest Suffolk

Partly sunny. A chance of Showers in the morning. Highs around 70. Chance of rain 30 percent.

Tonight 26 Sep Northwest Suffolk

Rain with isolated Thunderstorms. Rain may be heavy at Times after midnight. Very windy with Lows in the upper 50s. North Winds 30 to 40 Mph with Gusts up to 60 Mph. Chance of rain near 100 percent.

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Port Jefferson Temperature Statistics

September Temperature

Islip, Long Island Mac Arthur Airport (10.6 miles)

  • Lowest 15 September, 2026

    52.6 °F

  • Average September

    69.4 °F

  • Highest 10 September, 2026

    86.6 °F

Climate (2021–2026)

Islip, Long Island Mac Arthur Airport (10.6 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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