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.

Fair

34°F

1°C

Humidity 73%
Wind Speed SW 9 mph
Barometer 30.00 in (1015.9 mb)
Dewpoint 26°F (-3°C)
Visibility 10.00 mi
Wind Chill27°F (-3°C)
Last update 4 Dec 3:56 am EST
Extended Forecast for

Smithtown NY

  • Today

    Today: Sunny through mid morning, then becoming mostly cloudy, with a high near 40. Wind chill values between 20 and 30. Breezy, with a west wind 9 to 14 mph increasing to 16 to 21 mph in the afternoon. Winds could gust as high as 31 mph.

    High: 40 °F

    Mostly Sunny
    then Partly
    Sunny and
    Breezy

  • Tonight

    Tonight: Mostly clear, with a low around 17. Wind chill values between 5 and 10. Blustery, with a north wind 18 to 23 mph decreasing to 8 to 13 mph after midnight. Winds could gust as high as 33 mph.

    Low: 17 °F

    Mostly Clear
    and Blustery
    then Mostly
    Clear

  • Friday

    Friday: A 20 percent chance of light snow after 4pm. Increasing clouds, with a high near 35. Wind chill values between 10 and 20. Light and variable wind becoming southeast around 5 mph.

    High: 35 °F

    Sunny then
    Slight Chance
    Light Snow

  • Friday Night

    Friday Night: A 40 percent chance of light snow, mainly after 7pm. Mostly cloudy, with a low around 27. Calm wind.

    Low: 27 °F

    Chance Light
    Snow

  • Saturday

    Saturday: A 20 percent chance of light rain before 1pm. Mostly cloudy, with a high near 41. Calm wind becoming west around 6 mph in the morning.

    High: 41 °F

    Slight Chance
    Light Rain

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 28.

    Low: 28 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 42.

    High: 42 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 22.

    Low: 22 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 31.

    High: 31 °F

    Mostly Sunny

Detailed Forecast

Today
Sunny through mid morning, then becoming mostly cloudy, with a high near 40. Wind chill values between 20 and 30. Breezy, with a west wind 9 to 14 mph increasing to 16 to 21 mph in the afternoon. Winds could gust as high as 31 mph.
Tonight
Mostly clear, with a low around 17. Wind chill values between 5 and 10. Blustery, with a north wind 18 to 23 mph decreasing to 8 to 13 mph after midnight. Winds could gust as high as 33 mph.
Friday
A 20 percent chance of light snow after 4pm. Increasing clouds, with a high near 35. Wind chill values between 10 and 20. Light and variable wind becoming southeast around 5 mph.
Friday Night
A 40 percent chance of light snow, mainly after 7pm. Mostly cloudy, with a low around 27. Calm wind.
Saturday
A 20 percent chance of light rain before 1pm. Mostly cloudy, with a high near 41. Calm wind becoming west around 6 mph in the morning.
Saturday Night
Partly cloudy, with a low around 28.
Sunday
Partly sunny, with a high near 42.
Sunday Night
Mostly cloudy, with a low around 22.
Monday
Mostly sunny, with a high near 31.
Monday Night
Partly cloudy, with a low around 18.
Tuesday
Partly sunny, with a high near 40.
Tuesday Night
A 30 percent chance of snow. Mostly cloudy, with a low around 30.
Wednesday
A 30 percent chance of rain. Partly sunny, with a high near 45.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.86°N 73.19°W (Elev. 98 ft)
Last Update:
2:27 am EST Dec 4, 2025
Forecast Valid:
4am EST Dec 4, 2025-6pm EST Dec 10, 2025
 
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Additional Resources

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