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

62°F

17°C

Humidity 93%
Wind Speed S 9 mph
Barometer 30.07 in (1018.2 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Last update 4 Nov 7:56 pm EST
Extended Forecast for

Smithtown NY

  • Tonight

    Tonight: Partly cloudy, with a low around 59. Southwest wind around 6 mph.

    Low: 59 °F

    Partly Cloudy

  • Thursday

    Thursday: A 20 percent chance of rain after 10am. Mostly cloudy, with a high near 70. South wind 7 to 11 mph, with gusts as high as 21 mph.

    High: 70 °F

    Slight Chance
    Rain

  • Thursday Night

    Thursday Night: Rain likely, mainly after 1am. Mostly cloudy, with a steady temperature around 63. South wind 5 to 9 mph, with gusts as high as 20 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 63 °F

    Rain Likely

  • Friday

    Friday: Rain likely. Mostly cloudy, with a high near 69. Southwest wind 3 to 5 mph. Chance of precipitation is 70%. New precipitation amounts between a half and three quarters of an inch possible.

    High: 69 °F

    Rain Likely

  • Friday Night

    Friday Night: A 50 percent chance of rain before 1am. Mostly cloudy, with a low around 53. Calm wind.

    Low: 53 °F

    Chance Rain

  • Saturday

    Saturday: Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 44.

    Low: 44 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 59.

    High: 59 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 41.

    Low: 41 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 59. Southwest wind around 6 mph.
Thursday
A 20 percent chance of rain after 10am. Mostly cloudy, with a high near 70. South wind 7 to 11 mph, with gusts as high as 21 mph.
Thursday Night
Rain likely, mainly after 1am. Mostly cloudy, with a steady temperature around 63. South wind 5 to 9 mph, with gusts as high as 20 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday
Rain likely. Mostly cloudy, with a high near 69. Southwest wind 3 to 5 mph. Chance of precipitation is 70%. New precipitation amounts between a half and three quarters of an inch possible.
Friday Night
A 50 percent chance of rain before 1am. Mostly cloudy, with a low around 53. Calm wind.
Saturday
Mostly sunny, with a high near 65.
Saturday Night
Partly cloudy, with a low around 44.
Sunday
Mostly sunny, with a high near 59.
Sunday Night
Mostly clear, with a low around 41.
Monday
Sunny, with a high near 58.
Monday Night
Mostly clear, with a low around 41.
Tuesday
Sunny, with a high near 61.
Tuesday Night
Mostly clear, with a low around 41.
Veterans Day
Sunny, with a high near 59.
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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:
1:23 pm EST Nov 4, 2026
Forecast Valid:
8pm EST Nov 4, 2026-6pm EST Nov 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