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

82°F

28°C

Humidity 46%
Wind Speed SE 12 mph
Barometer 30.10 in (1019.2 mb)
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 4 Aug 2:56 pm EDT
Extended Forecast for

Setauket-East Setauket NY

  • Tonight

    Tonight: Mostly cloudy, with a low around 66. Southeast wind around 5 mph becoming calm in the evening.

    Low: 66 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon.

    High: 83 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 71. South wind around 6 mph.

    Low: 71 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Thursday

    Thursday: Mostly sunny, with a high near 87. Heat index values as high as 99. Southwest wind 5 to 11 mph.

    High: 87 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 73. Southwest wind 6 to 9 mph.

    Low: 73 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 89.

    High: 89 °F

    Mostly Sunny

  • Friday Night

    Friday Night: A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.

    Low: 72 °F

    Chance
    Showers

  • Saturday

    Saturday: Mostly sunny, with a high near 87.

    High: 87 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.

    Low: 72 °F

    Chance
    Showers

Detailed Forecast

Tonight
Mostly cloudy, with a low around 66. Southeast wind around 5 mph becoming calm in the evening.
Wednesday
Partly sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon.
Wednesday Night
A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 71. South wind around 6 mph.
Thursday
Mostly sunny, with a high near 87. Heat index values as high as 99. Southwest wind 5 to 11 mph.
Thursday Night
A 20 percent chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 73. Southwest wind 6 to 9 mph.
Friday
Mostly sunny, with a high near 89.
Friday Night
A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.
Saturday
Mostly sunny, with a high near 87.
Saturday Night
A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.
Sunday
Mostly sunny, with a high near 87.
Sunday Night
Mostly clear, with a low around 73.
Monday
Sunny, with a high near 89.
Monday Night
Partly cloudy, with a low around 72.
Tuesday
Mostly sunny, with a high near 86.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Setauket-East Setauket NY
 40.91°N 73.09°W (Elev. 197 ft)
Last Update:
6:53 am EDT Aug 4, 2026
Forecast Valid:
3pm EDT Aug 4, 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