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.

Light Snow

36°F

2°C

Humidity 73%
Wind Speed SW 20 G 30 mph
Barometer 29.75 in (1007.5 mb)
Dewpoint 28°F (-2°C)
Visibility 7.00 mi
Wind Chill25°F (-4°C)
Last update 25 Feb 6:56 am EST
Extended Forecast for

Port Jefferson NY

  • Today

    Today: Snow, possibly mixing with rain after 10am, then gradually ending. High near 39. Wind chill values between 25 and 30. Southwest wind 10 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. Total daytime snow accumulation of less than one inch possible.

    High: 39 °F

    Rain/Snow
    then Chance
    Rain/Snow

  • Tonight

    Tonight: Partly cloudy, with a low around 29. Southwest wind around 8 mph.

    Low: 29 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of snow after 1pm. Partly sunny, with a high near 36. Wind chill values between 25 and 35. West wind around 6 mph.

    High: 36 °F

    Mostly Sunny
    then Chance
    Snow

  • Thursday Night

    Thursday Night: A 20 percent chance of snow before 1am. Partly cloudy, with a low around 25. Calm wind.

    Low: 25 °F

    Slight Chance
    Snow

  • Friday

    Friday: Mostly sunny, with a high near 35. Calm wind becoming west around 6 mph.

    High: 35 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 27.

    Low: 27 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 43.

    High: 43 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 28.

    Low: 28 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 37.

    High: 37 °F

    Partly Sunny

Detailed Forecast

Today
Snow, possibly mixing with rain after 10am, then gradually ending. High near 39. Wind chill values between 25 and 30. Southwest wind 10 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. Total daytime snow accumulation of less than one inch possible.
Tonight
Partly cloudy, with a low around 29. Southwest wind around 8 mph.
Thursday
A 30 percent chance of snow after 1pm. Partly sunny, with a high near 36. Wind chill values between 25 and 35. West wind around 6 mph.
Thursday Night
A 20 percent chance of snow before 1am. Partly cloudy, with a low around 25. Calm wind.
Friday
Mostly sunny, with a high near 35. Calm wind becoming west around 6 mph.
Friday Night
Partly cloudy, with a low around 27.
Saturday
Mostly sunny, with a high near 43.
Saturday Night
Partly cloudy, with a low around 28.
Sunday
Partly sunny, with a high near 37.
Sunday Night
Partly cloudy, with a low around 19.
Monday
A 40 percent chance of snow. Mostly cloudy, with a high near 28.
Monday Night
A 30 percent chance of snow. Mostly cloudy, with a low around 19.
Tuesday
A 30 percent chance of snow. Partly sunny, with a high near 34.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
1:23 am EST Feb 25, 2026
Forecast Valid:
7am EST Feb 25, 2026-6pm EST Mar 3, 2026
 
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Additional Resources

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Chance of Precipitation