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.

Fog

49°F

9°C

Humidity 93%
Wind Speed SW 9 mph
Barometer 29.29 in (992.0 mb)
Dewpoint 47°F (8°C)
Visibility 0.50 mi
Wind Chill45°F (7°C)
Last update 29 Dec 12:56 pm EST
Extended Forecast for

Port Jefferson NY

Wind Advisory December 29, 04:00pm until December 30, 06:00pm
Click here for hazard details and duration
Wind Advisory

  • This Afternoon

    This Afternoon: Rain likely before 4pm. Mostly cloudy, with a high near 49. Breezy, with a west wind 16 to 25 mph. Chance of precipitation is 70%.

    High: 49 °F

    Rain Likely
    and Breezy

  • Tonight

    Tonight: Partly cloudy, with a low around 29. Wind chill values between 15 and 25. Windy, with a west wind around 34 mph, with gusts as high as 44 mph.

    Low: 29 °F

    Partly Cloudy
    and Windy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 32. Wind chill values between 15 and 20. Windy, with a west wind 29 to 32 mph, with gusts as high as 44 mph.

    High: 32 °F

    Mostly Cloudy
    and Windy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a steady temperature around 31. Wind chill values between 15 and 20. Windy, with a west wind 22 to 31 mph.

    Low: 31 °F

    Mostly Cloudy
    and Windy

  • Wednesday

    Wednesday: Partly sunny, with a high near 34. Breezy, with a west wind 18 to 20 mph.

    High: 34 °F

    Mostly Cloudy
    and Breezy
    then Partly
    Sunny

  • Wednesday Night

    Wednesday Night: A 30 percent chance of snow after 1am. Mostly cloudy, with a low around 26. Breezy.

    Low: 26 °F

    Breezy.
    Mostly Cloudy
    then Chance
    Snow

  • New Year's Day

    New Year's Day: Mostly sunny, with a high near 30.

    High: 30 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 22.

    Low: 22 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 32.

    High: 32 °F

    Partly Sunny

Detailed Forecast

This Afternoon
Rain likely before 4pm. Mostly cloudy, with a high near 49. Breezy, with a west wind 16 to 25 mph. Chance of precipitation is 70%.
Tonight
Partly cloudy, with a low around 29. Wind chill values between 15 and 25. Windy, with a west wind around 34 mph, with gusts as high as 44 mph.
Tuesday
Mostly cloudy, with a high near 32. Wind chill values between 15 and 20. Windy, with a west wind 29 to 32 mph, with gusts as high as 44 mph.
Tuesday Night
Mostly cloudy, with a steady temperature around 31. Wind chill values between 15 and 20. Windy, with a west wind 22 to 31 mph.
Wednesday
Partly sunny, with a high near 34. Breezy, with a west wind 18 to 20 mph.
Wednesday Night
A 30 percent chance of snow after 1am. Mostly cloudy, with a low around 26. Breezy.
New Year's Day
Mostly sunny, with a high near 30.
Thursday Night
Partly cloudy, with a low around 22.
Friday
Partly sunny, with a high near 32.
Friday Night
Partly cloudy, with a low around 28.
Saturday
Mostly sunny, with a high near 34.
Saturday Night
Partly cloudy, with a low around 25.
Sunday
Mostly sunny, with a high near 33.
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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:
1:24 pm EST Dec 29, 2025
Forecast Valid:
1pm EST Dec 29, 2025-6pm EST Jan 4, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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