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.

Partly Cloudy

74°F

23°C

Humidity 64%
Wind Speed SW 10 mph
Barometer 30.32 in (1026.7 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 16 Sep 1:56 pm EDT
Extended Forecast for

East Setauket NY

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 75. Southwest wind around 7 mph.

    High: 75 °F

    Mostly Sunny

  • Tonight

    Tonight: Patchy fog after 9pm. Otherwise, partly cloudy, with a low around 65. South wind 5 to 7 mph becoming calm after midnight.

    Low: 65 °F

    Patchy Fog

  • Thursday

    Thursday: Increasing clouds, with a high near 80. Calm wind becoming south 5 to 8 mph in the afternoon.

    High: 80 °F

    Increasing
    Clouds

  • Thursday Night

    Thursday Night: A 40 percent chance of showers, mainly before 2am. Mostly cloudy, with a low around 67. South wind 8 to 10 mph.

    Low: 67 °F

    Chance
    Showers

  • Friday

    Friday: Partly sunny through mid morning, then becoming sunny, with a high near 78. North wind 8 to 10 mph.

    High: 78 °F

    Becoming
    Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 58.

    Low: 58 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 69.

    High: 69 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 59.

    Low: 59 °F

    Mostly Cloudy

  • Sunday

    Sunday: Showers likely, mainly after 2pm. Mostly cloudy, with a high near 71. Chance of precipitation is 70%.

    High: 71 °F

    Showers
    Likely

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 75. Southwest wind around 7 mph.
Tonight
Patchy fog after 9pm. Otherwise, partly cloudy, with a low around 65. South wind 5 to 7 mph becoming calm after midnight.
Thursday
Increasing clouds, with a high near 80. Calm wind becoming south 5 to 8 mph in the afternoon.
Thursday Night
A 40 percent chance of showers, mainly before 2am. Mostly cloudy, with a low around 67. South wind 8 to 10 mph.
Friday
Partly sunny through mid morning, then becoming sunny, with a high near 78. North wind 8 to 10 mph.
Friday Night
Partly cloudy, with a low around 58.
Saturday
Mostly sunny, with a high near 69.
Saturday Night
Mostly cloudy, with a low around 59.
Sunday
Showers likely, mainly after 2pm. Mostly cloudy, with a high near 71. Chance of precipitation is 70%.
Sunday Night
Showers likely, mainly before 2am. Mostly cloudy, with a low around 60. Chance of precipitation is 60%.
Monday
A 30 percent chance of showers. Mostly cloudy, with a high near 70.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 59.
Tuesday
A 40 percent chance of showers. Mostly cloudy, with a high near 69.
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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:
2:25 pm EDT Sep 16, 2026
Forecast Valid:
2pm EDT Sep 16, 2026-6pm EDT Sep 22, 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