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.

Mostly Cloudy

17°F

-8°C

Humidity 49%
Wind Speed NW 9 mph
Barometer 30.00 in (1015.8 mb)
Dewpoint 1°F (-17°C)
Visibility 10.00 mi
Wind Chill6°F (-14°C)
Last update 28 Jan 9:56 pm EST
Extended Forecast for

Port Jefferson NY

  • Tonight

    Tonight: Mostly cloudy, with a low around 12. Wind chill values between 5 and 10. Northwest wind around 7 mph.

    Low: 12 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 22. Wind chill values between zero and 10. West wind 7 to 10 mph.

    High: 22 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 8. Wind chill values between -5 and 5. Northwest wind around 10 mph, with gusts as high as 21 mph.

    Low: 8 °F

    Mostly Clear

  • Friday

    Friday: Sunny and cold, with a high near 18. Wind chill values between -5 and 5. West wind 9 to 11 mph.

    High: 18 °F

    Cold

  • Friday Night

    Friday Night: Mostly clear, with a low around 6. Northwest wind 6 to 8 mph.

    Low: 6 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 21.

    High: 21 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 50 percent chance of snow after 1am. Mostly cloudy, with a low around 14. Blustery.

    Low: 14 °F

    Mostly Cloudy
    then Chance
    Snow and
    Blustery

  • Sunday

    Sunday: A 50 percent chance of snow. Cloudy, with a high near 26. Blustery.

    High: 26 °F

    Chance Snow
    and Blustery

  • Sunday Night

    Sunday Night: A 30 percent chance of snow before 1am. Mostly cloudy, with a low around 17. Blustery.

    Low: 17 °F

    Chance Snow
    and Blustery

Detailed Forecast

Tonight
Mostly cloudy, with a low around 12. Wind chill values between 5 and 10. Northwest wind around 7 mph.
Thursday
Mostly sunny, with a high near 22. Wind chill values between zero and 10. West wind 7 to 10 mph.
Thursday Night
Mostly clear, with a low around 8. Wind chill values between -5 and 5. Northwest wind around 10 mph, with gusts as high as 21 mph.
Friday
Sunny and cold, with a high near 18. Wind chill values between -5 and 5. West wind 9 to 11 mph.
Friday Night
Mostly clear, with a low around 6. Northwest wind 6 to 8 mph.
Saturday
Mostly sunny, with a high near 21.
Saturday Night
A 50 percent chance of snow after 1am. Mostly cloudy, with a low around 14. Blustery.
Sunday
A 50 percent chance of snow. Cloudy, with a high near 26. Blustery.
Sunday Night
A 30 percent chance of snow before 1am. Mostly cloudy, with a low around 17. Blustery.
Monday
Mostly sunny, with a high near 31.
Monday Night
Partly cloudy, with a low around 18.
Tuesday
Partly sunny, with a high near 32.
Tuesday Night
Partly cloudy, with a low around 16.
Wednesday
Mostly sunny, with a high near 29.
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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:
4:40 pm EST Jan 28, 2026
Forecast Valid:
10pm EST Jan 28, 2026-6pm EST Feb 4, 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