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.

Overcast

59°F

15°C

Humidity 90%
Wind Speed SW 16 G 25 mph
Barometer 29.89 in (1012.0 mb)
Dewpoint 56°F (13°C)
Visibility 9.00 mi
Last update 26 Nov 12:56 am EST
Extended Forecast for

Smithtown NY

  • Overnight

    Overnight: Rain likely, mainly before 4am. Cloudy, with a steady temperature around 54. South wind around 9 mph, with gusts as high as 21 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 54 °F

    Rain Likely

  • Wednesday

    Wednesday: A chance of rain before 7am, then a chance of showers after 4pm. Cloudy, with a high near 60. South wind 6 to 9 mph. Chance of precipitation is 50%.

    High: 60 °F

    Chance Rain

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 35. West wind 6 to 14 mph, with gusts as high as 29 mph.

    Low: 35 °F

    Chance
    Showers

  • Thanksgiving Day

    Thanksgiving Day: Mostly sunny, with a high near 44. West wind 14 to 17 mph, with gusts as high as 33 mph.

    High: 44 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 30. West wind around 16 mph, with gusts as high as 33 mph.

    Low: 30 °F

    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 43. Breezy.

    High: 43 °F

    Mostly Sunny
    then Mostly
    Sunny and
    Breezy

  • Friday Night

    Friday Night: Mostly clear, with a low around 29.

    Low: 29 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 42.

    High: 42 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 31.

    Low: 31 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Rain likely, mainly before 4am. Cloudy, with a steady temperature around 54. South wind around 9 mph, with gusts as high as 21 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday
A chance of rain before 7am, then a chance of showers after 4pm. Cloudy, with a high near 60. South wind 6 to 9 mph. Chance of precipitation is 50%.
Wednesday Night
A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 35. West wind 6 to 14 mph, with gusts as high as 29 mph.
Thanksgiving Day
Mostly sunny, with a high near 44. West wind 14 to 17 mph, with gusts as high as 33 mph.
Thursday Night
Mostly clear, with a low around 30. West wind around 16 mph, with gusts as high as 33 mph.
Friday
Mostly sunny, with a high near 43. Breezy.
Friday Night
Mostly clear, with a low around 29.
Saturday
Sunny, with a high near 42.
Saturday Night
Mostly cloudy, with a low around 31.
Sunday
A 30 percent chance of rain after 1pm. Mostly cloudy, with a high near 53.
Sunday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 38.
Monday
A 30 percent chance of rain. Mostly cloudy, with a high near 48.
Monday Night
Mostly cloudy, with a low around 32.
Tuesday
A 40 percent chance of rain. Mostly cloudy, 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:
4:54 pm EST Nov 25, 2025
Forecast Valid:
1am EST Nov 26, 2025-6pm EST Dec 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