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

29°F

-2°C

Humidity 47%
Wind Speed W 15 G 26 mph
Barometer 29.85 in (1011.0 mb)
Dewpoint 11°F (-12°C)
Visibility 10.00 mi
Wind Chill18°F (-8°C)
Last update 24 Feb 12:56 pm EST
Extended Forecast for

Port Jefferson NY

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 33. Wind chill values between 20 and 25. Breezy, with a west wind around 20 mph, with gusts as high as 31 mph.

    High: 33 °F

    Mostly Sunny
    and Breezy

  • Tonight

    Tonight: Snow likely after 4am. Increasing clouds, with a low around 18. Wind chill values between 10 and 15. West wind 12 to 17 mph becoming southwest 6 to 11 mph after midnight. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.

    Low: 18 °F

    Partly Cloudy
    then Snow
    Likely

  • Wednesday

    Wednesday: Rain and snow, mainly before 1pm. High near 39. Wind chill values between 20 and 30. Breezy, with a southwest wind 14 to 20 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.

    High: 39 °F

    Rain/Snow and
    Breezy then
    Chance
    Rain/Snow

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 29. Southwest wind around 14 mph.

    Low: 29 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of snow, mainly after 4pm. Partly sunny, with a high near 36. West wind 7 to 10 mph.

    High: 36 °F

    Mostly Sunny
    then Chance
    Snow

  • Thursday Night

    Thursday Night: A 40 percent chance of snow before 4am. Mostly cloudy, with a low around 25.

    Low: 25 °F

    Chance Snow

  • Friday

    Friday: Mostly sunny, with a high near 35.

    High: 35 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 31.

    Low: 31 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 41.

    High: 41 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 33. Wind chill values between 20 and 25. Breezy, with a west wind around 20 mph, with gusts as high as 31 mph.
Tonight
Snow likely after 4am. Increasing clouds, with a low around 18. Wind chill values between 10 and 15. West wind 12 to 17 mph becoming southwest 6 to 11 mph after midnight. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
Wednesday
Rain and snow, mainly before 1pm. High near 39. Wind chill values between 20 and 30. Breezy, with a southwest wind 14 to 20 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
Wednesday Night
Partly cloudy, with a low around 29. Southwest wind around 14 mph.
Thursday
A 30 percent chance of snow, mainly after 4pm. Partly sunny, with a high near 36. West wind 7 to 10 mph.
Thursday Night
A 40 percent chance of snow before 4am. Mostly cloudy, with a low around 25.
Friday
Mostly sunny, with a high near 35.
Friday Night
Partly cloudy, with a low around 31.
Saturday
Mostly sunny, with a high near 41.
Saturday Night
Partly cloudy, with a low around 32.
Sunday
Partly sunny, with a high near 37.
Sunday Night
Partly cloudy, with a low around 22.
Monday
A 40 percent chance of snow. Partly sunny, with a high near 29.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.96°N 73.08°W (Elev. 3 ft)
Last Update:
1:21 pm EST Feb 24, 2026
Forecast Valid:
1pm EST Feb 24, 2026-6pm EST Mar 2, 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