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.

Fair

15°F

-9°C

Humidity 53%
Wind Speed NW 15 mph
Barometer 30.07 in (1018.4 mb)
Dewpoint 1°F (-17°C)
Visibility 10.00 mi
Wind Chill0°F (-18°C)
Last update 28 Jan 2:56 am EST
Extended Forecast for

Port Jefferson NY

  • Overnight

    Overnight: Clear, with a low around 12. Wind chill values between zero and 5. West wind around 14 mph, with gusts as high as 24 mph.

    Low: 12 °F

    Clear

  • Wednesday

    Wednesday: Increasing clouds, with a high near 23. Wind chill values between zero and 10. West wind 6 to 10 mph, with gusts as high as 20 mph.

    High: 23 °F

    Increasing
    Clouds

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 10. Wind chill values between zero and 5. West wind 7 to 9 mph becoming northwest after midnight.

    Low: 10 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 22. Wind chill values between zero and 10. West wind 9 to 11 mph.

    High: 22 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 8. West wind 9 to 11 mph.

    Low: 8 °F

    Mostly Clear

  • Friday

    Friday: Sunny and cold, with a high near 19.

    High: 19 °F

    Cold

  • Friday Night

    Friday Night: Mostly clear, with a low around 5.

    Low: 5 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 21.

    High: 21 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of snow after 1am. Mostly cloudy, with a low around 14.

    Low: 14 °F

    Mostly Cloudy
    then Chance
    Snow

Detailed Forecast

Overnight
Clear, with a low around 12. Wind chill values between zero and 5. West wind around 14 mph, with gusts as high as 24 mph.
Wednesday
Increasing clouds, with a high near 23. Wind chill values between zero and 10. West wind 6 to 10 mph, with gusts as high as 20 mph.
Wednesday Night
Mostly cloudy, with a low around 10. Wind chill values between zero and 5. West wind 7 to 9 mph becoming northwest after midnight.
Thursday
Mostly sunny, with a high near 22. Wind chill values between zero and 10. West wind 9 to 11 mph.
Thursday Night
Mostly clear, with a low around 8. West wind 9 to 11 mph.
Friday
Sunny and cold, with a high near 19.
Friday Night
Mostly clear, with a low around 5.
Saturday
Mostly sunny, with a high near 21.
Saturday Night
A 30 percent chance of snow after 1am. Mostly cloudy, with a low around 14.
Sunday
A 50 percent chance of snow. Cloudy, with a high near 27.
Sunday Night
A 30 percent chance of snow. Mostly cloudy, with a low around 17.
Monday
Mostly sunny, with a high near 31.
Monday Night
Partly cloudy, with a low around 19.
Tuesday
Mostly sunny, with a high near 31.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
1:25 am EST Jan 28, 2026
Forecast Valid:
3am EST Jan 28, 2026-6pm EST Feb 3, 2026
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation