Port Jefferson Weather Forecast

    • 40
    • 52

    Mostly Cloudy

    • 39
    • 53

    Rain

    • 33
    • 44

    Chance Rain

    • 37
    • 44

    Partly Sunny

    • 38
    • 49

    Mostly Cloudy

    • 41
    • 49

    Rain Likely

    • 31
    • 46

    Slight Chance Rain/Snow

Today 21 Mar Northwest Suffolk

Mostly sunny. Highs in the mid 50s. North Winds 5 to 10 Mph.

Tonight 21 Mar Northwest Suffolk

Partly cloudy this Evening, then becoming mostly cloudy. Lows in the upper 30s. Northeast Winds 10 to 15 Mph, becoming southeast 5 to 10 Mph after midnight.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Port Jefferson Temperature Statistics

March Temperature

Islip, Long Island Mac Arthur Airport (10.6 miles)

  • Lowest 3 March, 2026

    18.6 °F

  • Average March

    40.2 °F

  • Highest 9 March, 2026

    68.6 °F

Climate (2021–Present)

Islip, Long Island Mac Arthur Airport (10.6 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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