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 and Breezy

32°F

0°C

Humidity 40%
Wind Speed NW 21 G 32 mph
Barometer 30.17 in (1021.7 mb)
Dewpoint 10°F (-12°C)
Visibility 10.00 mi
Wind Chill20°F (-7°C)
Last update 4 Dec 7:56 pm EST
Extended Forecast for

Smithtown NY

  • Tonight

    Tonight: Partly cloudy, with a low around 16. Wind chill values between 10 and 15. North wind 13 to 18 mph decreasing to 7 to 12 mph after midnight. Winds could gust as high as 29 mph.

    Low: 16 °F

    Partly Cloudy

  • Friday

    Friday: Increasing clouds, with a high near 34. Wind chill values between 15 and 25. Calm wind becoming southeast around 5 mph.

    High: 34 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: A chance of snow before 1am, then a chance of rain. Mostly cloudy, with a steady temperature around 31. Calm wind. Chance of precipitation is 30%.

    Low: 31 °F

    Chance Snow
    then Chance
    Rain/Snow

  • Saturday

    Saturday: A 20 percent chance of rain before 1pm. Mostly cloudy, with a high near 42. Calm wind becoming west 5 to 7 mph in the afternoon.

    High: 42 °F

    Slight Chance
    Rain

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 29. West wind 3 to 5 mph.

    Low: 29 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 41.

    High: 41 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 25.

    Low: 25 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 35.

    High: 35 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 18.

    Low: 18 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 16. Wind chill values between 10 and 15. North wind 13 to 18 mph decreasing to 7 to 12 mph after midnight. Winds could gust as high as 29 mph.
Friday
Increasing clouds, with a high near 34. Wind chill values between 15 and 25. Calm wind becoming southeast around 5 mph.
Friday Night
A chance of snow before 1am, then a chance of rain. Mostly cloudy, with a steady temperature around 31. Calm wind. Chance of precipitation is 30%.
Saturday
A 20 percent chance of rain before 1pm. Mostly cloudy, with a high near 42. Calm wind becoming west 5 to 7 mph in the afternoon.
Saturday Night
Partly cloudy, with a low around 29. West wind 3 to 5 mph.
Sunday
Partly sunny, with a high near 41.
Sunday Night
Mostly cloudy, with a low around 25.
Monday
Mostly sunny, with a high near 35.
Monday Night
Mostly clear, with a low around 18.
Tuesday
Partly sunny, with a high near 39.
Tuesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 30.
Wednesday
Mostly cloudy, with a high near 44.
Wednesday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 33.
Thursday
A 50 percent chance of rain. Mostly cloudy, with a high near 44.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.86°N 73.19°W (Elev. 98 ft)
Last Update:
8:07 pm EST Dec 4, 2025
Forecast Valid:
8pm EST Dec 4, 2025-6pm EST Dec 11, 2025
 
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Additional Resources

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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