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.

Mostly Cloudy

70°F

21°C

Humidity 82%
Wind Speed E 10 mph
Barometer 30.06 in (1017.7 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 26 Jun 8:56 am EDT
Extended Forecast for

Smithtown NY

  • Today

    Today: A 30 percent chance of showers, mainly between 11am and 2pm. Mostly cloudy, with a high near 79. East wind 11 to 13 mph.

    High: 79 °F

    Chance
    Showers

  • Tonight

    Tonight: A 20 percent chance of showers. Mostly cloudy, with a low around 64. East wind 8 to 10 mph.

    Low: 64 °F

    Slight Chance
    Showers

  • Friday

    Friday: A 20 percent chance of showers after 2pm. Mostly cloudy, with a high near 72. East wind 10 to 13 mph.

    High: 72 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms, mainly after 8pm. Cloudy, with a low around 63. East wind 6 to 9 mph.

    Low: 63 °F

    Chance
    Showers

  • Saturday

    Saturday: A slight chance of showers, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 80. South wind 5 to 8 mph. Chance of precipitation is 40%.

    High: 80 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.

    Low: 67 °F

    Chance
    T-storms

  • Sunday

    Sunday: Partly sunny, with a high near 81.

    High: 81 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 66.

    Low: 66 °F

    Mostly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 83.

    High: 83 °F

    Partly Sunny

Detailed Forecast

Today
A 30 percent chance of showers, mainly between 11am and 2pm. Mostly cloudy, with a high near 79. East wind 11 to 13 mph.
Tonight
A 20 percent chance of showers. Mostly cloudy, with a low around 64. East wind 8 to 10 mph.
Friday
A 20 percent chance of showers after 2pm. Mostly cloudy, with a high near 72. East wind 10 to 13 mph.
Friday Night
A 30 percent chance of showers and thunderstorms, mainly after 8pm. Cloudy, with a low around 63. East wind 6 to 9 mph.
Saturday
A slight chance of showers, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 80. South wind 5 to 8 mph. Chance of precipitation is 40%.
Saturday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.
Sunday
Partly sunny, with a high near 81.
Sunday Night
Mostly cloudy, with a low around 66.
Monday
Partly sunny, with a high near 83.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 69.
Tuesday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 85.
Tuesday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71.
Wednesday
Mostly sunny, with a high near 87.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.84°N 73.22°W (Elev. 49 ft)
Last Update:
6:09 am EDT Jun 26, 2025
Forecast Valid:
9am EDT Jun 26, 2025-6pm EDT Jul 2, 2025
 
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