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.

A Few Clouds

30°F

-1°C

Humidity 43%
Wind Speed N 8 mph
Barometer 29.96 in (1014.6 mb)
Dewpoint 10°F (-12°C)
Visibility 10.00 mi
Wind Chill22°F (-6°C)
Last update 5 Feb 2:56 pm EST
Extended Forecast for

Port Jefferson NY

Extreme Cold Watch February 7, 06:00pm until February 8, 01:00pm
Click here for hazard details and duration
Extreme Cold Watch

  • Tonight

    Tonight: Increasing clouds, with a low around 21. Wind chill values between 10 and 15. Northeast wind 5 to 9 mph.

    Low: 21 °F

    Increasing
    Clouds

  • Friday

    Friday: Mostly cloudy, with a high near 28. Wind chill values between 10 and 20. Northeast wind 5 to 9 mph becoming calm in the afternoon.

    High: 28 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: Snow, mainly after 1am. Steady temperature around 27. Wind chill values between 20 and 25. Calm wind becoming west around 6 mph after midnight. Chance of precipitation is 80%. New snow accumulation of less than one inch possible.

    Low: 27 °F

    Chance Snow
    then Snow

  • Saturday

    Saturday: Snow, mainly before 1pm. Temperature falling to around 16 by 5pm. Wind chill values between -5 and 5. Windy, with a northwest wind 11 to 21 mph increasing to 29 to 39 mph. Winds could gust as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of around an inch possible.

    High: 27 °F⇓

    Snow and
    Windy

  • Saturday Night

    Saturday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 8. Very windy, with a northwest wind 38 to 43 mph decreasing to 32 to 37 mph after midnight.

    Low: 8 °F

    Decreasing
    Clouds and
    Very Windy

  • Sunday

    Sunday: Sunny and cold, with a high near 17. Windy.

    High: 17 °F

    Cold and
    Windy

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 11. Blustery.

    Low: 11 °F

    Mostly Clear
    and Blustery

  • Monday

    Monday: Mostly sunny, with a high near 24.

    High: 24 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 16.

    Low: 16 °F

    Partly Cloudy

Detailed Forecast

Tonight
Increasing clouds, with a low around 21. Wind chill values between 10 and 15. Northeast wind 5 to 9 mph.
Friday
Mostly cloudy, with a high near 28. Wind chill values between 10 and 20. Northeast wind 5 to 9 mph becoming calm in the afternoon.
Friday Night
Snow, mainly after 1am. Steady temperature around 27. Wind chill values between 20 and 25. Calm wind becoming west around 6 mph after midnight. Chance of precipitation is 80%. New snow accumulation of less than one inch possible.
Saturday
Snow, mainly before 1pm. Temperature falling to around 16 by 5pm. Wind chill values between -5 and 5. Windy, with a northwest wind 11 to 21 mph increasing to 29 to 39 mph. Winds could gust as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of around an inch possible.
Saturday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 8. Very windy, with a northwest wind 38 to 43 mph decreasing to 32 to 37 mph after midnight.
Sunday
Sunny and cold, with a high near 17. Windy.
Sunday Night
Mostly clear, with a low around 11. Blustery.
Monday
Mostly sunny, with a high near 24.
Monday Night
Partly cloudy, with a low around 16.
Tuesday
Mostly sunny, with a high near 28.
Tuesday Night
Mostly cloudy, with a low around 23.
Wednesday
A 30 percent chance of rain. Mostly sunny, with a high near 34.
Wednesday Night
Mostly cloudy, with a low around 28.
Thursday
Mostly cloudy, with a high near 36.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.96°N 73.08°W (Elev. 3 ft)
Last Update:
1:09 pm EST Feb 5, 2026
Forecast Valid:
3pm EST Feb 5, 2026-6pm EST Feb 12, 2026
 
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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