National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

A Few Clouds

26°F

-3°C

Humidity 69%
Wind Speed Calm
Barometer 30.39 in (1029.4 mb)
Dewpoint 17°F (-8°C)
Visibility 10.00 mi
Last update 18 Mar 10:56 pm EDT
Extended Forecast for

East Setauket NY

  • Tonight

    Tonight: Mostly clear, with a low around 26. Calm wind.

    Low: 26 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 42. Calm wind becoming south around 6 mph in the afternoon.

    High: 42 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 34. South wind 3 to 5 mph.

    Low: 34 °F

    Mostly Cloudy

  • Friday

    Friday: Increasing clouds, with a high near 50. Calm wind becoming south 5 to 7 mph in the afternoon.

    High: 50 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Rain likely, mainly after midnight. Mostly cloudy, with a low around 40. South wind around 9 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 40 °F

    Rain Likely

  • Saturday

    Saturday: A 30 percent chance of rain before 8am. Partly sunny, with a high near 52.

    High: 52 °F

    Chance Rain
    then Partly
    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 40.

    Low: 40 °F

    Mostly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 55.

    High: 55 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: A 30 percent chance of rain. Mostly cloudy, with a low around 36.

    Low: 36 °F

    Chance Rain

Detailed Forecast

Tonight
Mostly clear, with a low around 26. Calm wind.
Thursday
Mostly sunny, with a high near 42. Calm wind becoming south around 6 mph in the afternoon.
Thursday Night
Mostly cloudy, with a low around 34. South wind 3 to 5 mph.
Friday
Increasing clouds, with a high near 50. Calm wind becoming south 5 to 7 mph in the afternoon.
Friday Night
Rain likely, mainly after midnight. Mostly cloudy, with a low around 40. South wind around 9 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
A 30 percent chance of rain before 8am. Partly sunny, with a high near 52.
Saturday Night
Mostly cloudy, with a low around 40.
Sunday
Partly sunny, with a high near 55.
Sunday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 36.
Monday
Mostly sunny, with a high near 47.
Monday Night
Partly cloudy, with a low around 29.
Tuesday
Mostly sunny, with a high near 41.
Tuesday Night
Mostly cloudy, with a low around 32.
Wednesday
Partly sunny, with a high near 48.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
East Setauket NY
 40.94°N 73.11°W (Elev. 52 ft)
Last Update:
5:35 pm EDT Mar 18, 2026
Forecast Valid:
11pm EDT Mar 18, 2026-6pm EDT Mar 25, 2026
 
Forecast Discussion
 
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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

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation