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

67°F

19°C

Humidity 84%
Wind Speed Calm
Barometer 30.12 in (1019.8 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Last update 4 Aug 11:56 pm EDT
Extended Forecast for

East Setauket NY

  • Overnight

    Overnight: Mostly cloudy, with a steady temperature around 69. Calm wind.

    Low: 69 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 84. Calm wind becoming southwest around 5 mph in the afternoon.

    High: 84 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms, then a chance of showers after 11pm. Mostly cloudy, with a low around 72. South wind around 6 mph. Chance of precipitation is 40%.

    Low: 72 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: A chance of showers before 8am, then a slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Heat index values as high as 98. Southwest wind 5 to 9 mph. Chance of precipitation is 30%.

    High: 88 °F

    Chance
    Showers then
    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Partly cloudy, with a low around 74. Southwest wind 6 to 8 mph. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    Showers

  • Friday

    Friday: A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 89.

    High: 89 °F

    Sunny then
    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 73.

    Low: 73 °F

    Chance
    Showers then
    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 73.

    Low: 73 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a steady temperature around 69. Calm wind.
Wednesday
Mostly sunny, with a high near 84. Calm wind becoming southwest around 5 mph in the afternoon.
Wednesday Night
A slight chance of showers and thunderstorms, then a chance of showers after 11pm. Mostly cloudy, with a low around 72. South wind around 6 mph. Chance of precipitation is 40%.
Thursday
A chance of showers before 8am, then a slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Heat index values as high as 98. Southwest wind 5 to 9 mph. Chance of precipitation is 30%.
Thursday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Partly cloudy, with a low around 74. Southwest wind 6 to 8 mph. Chance of precipitation is 30%.
Friday
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 89.
Friday Night
A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 73.
Saturday
Mostly sunny, with a high near 88.
Saturday Night
Mostly cloudy, with a low around 73.
Sunday
Mostly sunny, with a high near 88.
Sunday Night
Partly cloudy, with a low around 73.
Monday
Sunny, with a high near 89.
Monday Night
Partly cloudy, with a low around 73.
Tuesday
A 40 percent chance of showers. Mostly sunny, with a high near 88.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
East Setauket NY
 40.94°N 73.11°W (Elev. 52 ft)
Last Update:
4:10 pm EDT Aug 4, 2026
Forecast Valid:
12am EDT Aug 5, 2026-6pm EDT Aug 11, 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