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

42°F

6°C

Humidity 47%
Wind Speed NW 13 mph
Barometer 30.03 in (1016.9 mb)
Dewpoint 23°F (-5°C)
Visibility 10.00 mi
Wind Chill35°F (2°C)
Last update 14 Feb 3:56 pm EST
Extended Forecast for

Port Jefferson NY

  • Tonight

    Tonight: Mostly clear, with a low around 25. West wind around 5 mph becoming calm in the evening.

    Low: 25 °F

    Mostly Clear

  • Sunday

    Sunday: Increasing clouds, with a high near 36. Calm wind becoming northeast around 6 mph in the afternoon.

    High: 36 °F

    Increasing
    Clouds

  • Sunday Night

    Sunday Night: Snow likely, mainly after 1am. Cloudy, with a low around 27. East wind 3 to 6 mph. Chance of precipitation is 60%. New snow accumulation of around an inch possible.

    Low: 27 °F

    Snow Likely

  • Washington's Birthday

    Washington's Birthday: A 20 percent chance of snow before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 36. Wind chill values between 20 and 30. Northeast wind 6 to 8 mph.

    High: 36 °F

    Slight Chance
    Snow

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 28. Calm wind.

    Low: 28 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 39.

    High: 39 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 31.

    Low: 31 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 50 percent chance of rain after 1pm. Mostly cloudy, with a high near 39.

    High: 39 °F

    Cloudy then
    Chance Rain

  • Wednesday Night

    Wednesday Night: A 50 percent chance of rain. Mostly cloudy, with a low around 32.

    Low: 32 °F

    Chance Rain

Detailed Forecast

Tonight
Mostly clear, with a low around 25. West wind around 5 mph becoming calm in the evening.
Sunday
Increasing clouds, with a high near 36. Calm wind becoming northeast around 6 mph in the afternoon.
Sunday Night
Snow likely, mainly after 1am. Cloudy, with a low around 27. East wind 3 to 6 mph. Chance of precipitation is 60%. New snow accumulation of around an inch possible.
Washington's Birthday
A 20 percent chance of snow before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 36. Wind chill values between 20 and 30. Northeast wind 6 to 8 mph.
Monday Night
Mostly cloudy, with a low around 28. Calm wind.
Tuesday
Partly sunny, with a high near 39.
Tuesday Night
Mostly cloudy, with a low around 31.
Wednesday
A 50 percent chance of rain after 1pm. Mostly cloudy, with a high near 39.
Wednesday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 32.
Thursday
A 30 percent chance of rain. Partly sunny, with a high near 42.
Thursday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 31.
Friday
A 50 percent chance of rain. Mostly cloudy, with a high near 41.
Friday Night
A chance of rain and snow. Mostly cloudy, with a low around 29. Chance of precipitation is 40%.
Saturday
A 30 percent chance of rain. Mostly cloudy, with a high near 40.
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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:
1:38 pm EST Feb 14, 2026
Forecast Valid:
4pm EST Feb 14, 2026-6pm EST Feb 21, 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