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

30°F

-1°C

Humidity 54%
Wind Speed NW 17 mph
Barometer 30.19 in (1022.5 mb)
Dewpoint 15°F (-9°C)
Visibility 10.00 mi
Wind Chill18°F (-8°C)
Last update 4 Feb 9:56 am EST
Extended Forecast for

Port Jefferson NY

  • Today

    Today: Sunny, with a high near 31. Wind chill values between 15 and 20. Northwest wind 10 to 13 mph.

    High: 31 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 15. North wind 3 to 7 mph.

    Low: 15 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 31. Wind chill values between 10 and 20. North wind around 6 mph.

    High: 31 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 15. Light north wind.

    Low: 15 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 28. Light and variable wind becoming west around 5 mph.

    High: 28 °F

    Partly Sunny

  • Friday Night

    Friday Night: Snow showers likely, mainly after 1am. Mostly cloudy, with a steady temperature around 23. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.

    Low: 23 °F

    Chance Snow
    Showers then
    Snow Showers
    Likely

  • Saturday

    Saturday: A 30 percent chance of snow showers before noon. Partly sunny, with a high near 25. Blustery.

    High: 25 °F

    Blustery.
    Chance Snow
    Showers then
    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 5. Blustery.

    Low: 5 °F

    Mostly Clear
    and Blustery

  • Sunday

    Sunday: Mostly sunny and cold, with a high near 18.

    High: 18 °F

    Cold

Detailed Forecast

Today
Sunny, with a high near 31. Wind chill values between 15 and 20. Northwest wind 10 to 13 mph.
Tonight
Partly cloudy, with a low around 15. North wind 3 to 7 mph.
Thursday
Sunny, with a high near 31. Wind chill values between 10 and 20. North wind around 6 mph.
Thursday Night
Partly cloudy, with a low around 15. Light north wind.
Friday
Partly sunny, with a high near 28. Light and variable wind becoming west around 5 mph.
Friday Night
Snow showers likely, mainly after 1am. Mostly cloudy, with a steady temperature around 23. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Saturday
A 30 percent chance of snow showers before noon. Partly sunny, with a high near 25. Blustery.
Saturday Night
Mostly clear, with a low around 5. Blustery.
Sunday
Mostly sunny and cold, with a high near 18.
Sunday Night
Partly cloudy, with a low around 8.
Monday
Mostly sunny, with a high near 24.
Monday Night
Partly cloudy, with a low around 14.
Tuesday
Mostly sunny, with a high near 30.
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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:
7:42 am EST Feb 4, 2026
Forecast Valid:
10am EST Feb 4, 2026-6pm EST Feb 10, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation