Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Partly Cloudy

37°F

3°C

Humidity 79%
Wind Speed W 6 mph
Barometer 29.73 in (1006.7 mb)
Dewpoint 31°F (-1°C)
Visibility 10.00 mi
Wind Chill32°F (0°C)
Last update 26 Feb 12:56 am EST
Extended Forecast for

Port Jefferson NY

  • Overnight

    Overnight: Partly cloudy, with a low around 33. West wind around 14 mph.

    Low: 33 °F

    Partly Cloudy

  • Thursday

    Thursday: A 20 percent chance of snow after 1pm.  Increasing clouds, with a high near 36. West wind 6 to 10 mph.

    High: 36 °F

    Mostly Sunny
    then Slight
    Chance Snow

  • Thursday Night

    Thursday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 24. North wind around 6 mph.

    Low: 24 °F

    Decreasing
    Clouds

  • Friday

    Friday: Sunny, with a high near 36. Wind chill values between 20 and 30. Calm wind becoming south around 6 mph in the afternoon.

    High: 36 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 32. South wind around 7 mph.

    Low: 32 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 42.

    High: 42 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 31.

    Low: 31 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 35.

    High: 35 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 20. Blustery.

    Low: 20 °F

    Mostly Clear
    and Blustery
    then Partly
    Cloudy

Detailed Forecast

Overnight
Partly cloudy, with a low around 33. West wind around 14 mph.
Thursday
A 20 percent chance of snow after 1pm. Increasing clouds, with a high near 36. West wind 6 to 10 mph.
Thursday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 24. North wind around 6 mph.
Friday
Sunny, with a high near 36. Wind chill values between 20 and 30. Calm wind becoming south around 6 mph in the afternoon.
Friday Night
Mostly clear, with a low around 32. South wind around 7 mph.
Saturday
Sunny, with a high near 42.
Saturday Night
Increasing clouds, with a low around 31.
Sunday
Mostly cloudy, with a high near 35.
Sunday Night
Partly cloudy, with a low around 20. Blustery.
Monday
A 30 percent chance of snow. Mostly cloudy, with a high near 26.
Monday Night
Mostly cloudy, with a low around 22.
Tuesday
Mostly cloudy, with a high near 34.
Tuesday Night
A 50 percent chance of rain. Cloudy, with a low around 31.
Wednesday
A 50 percent chance of rain. Mostly sunny, with a high near 40.
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.96°N 73.08°W (Elev. 3 ft)
12:57 am EST Feb 26, 2026
1am EST Feb 26, 2026-6pm EST Mar 4, 2026
 
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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