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

11°F

-12°C

Humidity 53%
Wind Speed NW 16 mph
Barometer 30.22 in (1023.5 mb)
Dewpoint -3°F (-19°C)
Visibility 10.00 mi
Wind Chill-6°F (-21°C)
Last update 9 Feb 5:56 am EST
Extended Forecast for

Port Jefferson NY

Cold Weather Advisory February 9, 06:13am until February 9, 10:00am
Click here for hazard details and duration
...
  •  
    Cold Weather Advisory February 9, 06:13am until February 9, 10:00am

    NOW until 10:00am Mon

    Cold Weather Advisory

  • Today

    High: 27 °F

    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 18. Northwest wind around 5 mph becoming calm in the evening.

    Low: 18 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: A 20 percent chance of snow after 1pm. Increasing clouds, with a high near 35. Wind chill values between 20 and 30. Calm wind becoming southwest around 6 mph in the afternoon.

    High: 35 °F

    Partly Sunny
    then Slight
    Chance Snow

  • Tuesday Night

    Tuesday Night: A chance of snow, mixing with rain after 10pm, then gradually ending. Cloudy, then gradually becoming partly cloudy, with a low around 27. Calm wind becoming west around 6 mph after midnight. Chance of precipitation is 30%.

    Low: 27 °F

    Chance
    Rain/Snow

  • Wednesday

    Wednesday: Mostly sunny, with a high near 36. West wind 6 to 11 mph.

    High: 36 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 23.

    Low: 23 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 33.

    High: 33 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 19.

    Low: 19 °F

    Partly Cloudy

Detailed Forecast

Today
Sunny, with a high near 27. Wind chill values between -5 and 5. Northwest wind 8 to 10 mph.
Tonight
Increasing clouds, with a low around 18. Northwest wind around 5 mph becoming calm in the evening.
Tuesday
A 20 percent chance of snow after 1pm. Increasing clouds, with a high near 35. Wind chill values between 20 and 30. Calm wind becoming southwest around 6 mph in the afternoon.
Tuesday Night
A chance of snow, mixing with rain after 10pm, then gradually ending. Cloudy, then gradually becoming partly cloudy, with a low around 27. Calm wind becoming west around 6 mph after midnight. Chance of precipitation is 30%.
Wednesday
Mostly sunny, with a high near 36. West wind 6 to 11 mph.
Wednesday Night
Partly cloudy, with a low around 23.
Thursday
Mostly sunny, with a high near 33.
Thursday Night
Partly cloudy, with a low around 19.
Friday
Mostly sunny, with a high near 32.
Friday Night
Mostly clear, with a low around 20.
Saturday
Sunny, with a high near 34.
Saturday Night
Partly cloudy, with a low around 22.
Sunday
A chance of rain and snow. Mostly cloudy, with a high near 35. Chance of precipitation is 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:
1:31 am EST Feb 9, 2026
Forecast Valid:
6am EST Feb 9, 2026-6pm EST Feb 15, 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