National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Partly Cloudy

32°F

0°C

Humidity 41%
Wind Speed W 16 mph
Barometer 29.75 in
Dewpoint 11°F (-12°C)
Visibility 10.00 mi
Wind Chill21°F (-6°C)
Last update 31 Dec 3:56 pm EST
Extended Forecast for

Port Jefferson NY

  • Tonight

    Tonight: Light snow, mainly between 10pm and 4am. Steady temperature around 34. Wind chill values between 20 and 25. Breezy, with a southwest wind 15 to 22 mph. Chance of precipitation is 80%. Total nighttime snow accumulation of less than one inch possible.

    Low: 34 °F

    Chance Light
    Snow then
    Light Snow
    and Breezy

  • New Year's Day

    New Year's Day: A 50 percent chance of snow showers before 10am. Mostly sunny, with a temperature falling to around 24 by 2pm. Wind chill values between 10 and 20. Windy, with a west wind 26 to 28 mph.

    High: 32 °F⇓

    Windy. Chance
    Snow Showers
    then Mostly
    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 22. Wind chill values between 5 and 10. Breezy, with a west wind 17 to 23 mph.

    Low: 22 °F

    Partly Cloudy
    and Breezy
    then Partly
    Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 30. Wind chill values between 10 and 20. West wind around 17 mph.

    High: 30 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 26. West wind around 15 mph.

    Low: 26 °F

    Partly Cloudy

  • Saturday

    Saturday: Increasing clouds, with a high near 32.

    High: 32 °F

    Increasing
    Clouds

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 28.

    Low: 28 °F

    Mostly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 34.

    High: 34 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 23.

    Low: 23 °F

    Mostly Clear

Detailed Forecast

Tonight
Light snow, mainly between 10pm and 4am. Steady temperature around 34. Wind chill values between 20 and 25. Breezy, with a southwest wind 15 to 22 mph. Chance of precipitation is 80%. Total nighttime snow accumulation of less than one inch possible.
New Year's Day
A 50 percent chance of snow showers before 10am. Mostly sunny, with a temperature falling to around 24 by 2pm. Wind chill values between 10 and 20. Windy, with a west wind 26 to 28 mph.
Thursday Night
Partly cloudy, with a low around 22. Wind chill values between 5 and 10. Breezy, with a west wind 17 to 23 mph.
Friday
Mostly sunny, with a high near 30. Wind chill values between 10 and 20. West wind around 17 mph.
Friday Night
Partly cloudy, with a low around 26. West wind around 15 mph.
Saturday
Increasing clouds, with a high near 32.
Saturday Night
Mostly cloudy, with a low around 28.
Sunday
Mostly sunny, with a high near 34.
Sunday Night
Mostly clear, with a low around 23.
Monday
Partly sunny, with a high near 33.
Monday Night
Mostly cloudy, with a low around 29.
Tuesday
Partly sunny, with a high near 38.
Tuesday Night
Mostly cloudy, with a low around 33.
Wednesday
A 30 percent chance of rain. Mostly cloudy, with a high near 42.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.96°N 73.08°W (Elev. 3 ft)
Last Update:
1:50 pm EST Dec 31, 2025
Forecast Valid:
4pm EST Dec 31, 2025-6pm EST Jan 7, 2026
 
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Additional Resources

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Chance of Precipitation