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

48°F

9°C

Humidity 96%
Wind Speed W 3 mph
Barometer 30.30 in (1026.2 mb)
Dewpoint 47°F (8°C)
Visibility 9.00 mi
Last update 3 Nov 6:56 am EST
Extended Forecast for

Smithtown NY

  • Today

    Today: Sunny, with a high near 69. Light southwest wind increasing to 5 to 10 mph in the morning.

    High: 69 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 52. South wind 3 to 6 mph.

    Low: 52 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 72. Calm wind becoming southwest 5 to 8 mph in the morning.

    High: 72 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 56. South wind 3 to 5 mph.

    Low: 56 °F

    Mostly Cloudy

  • Thursday

    Thursday: A 20 percent chance of showers after 9am. Mostly cloudy, with a high near 70. South wind 5 to 10 mph.

    High: 70 °F

    Slight Chance
    Showers

  • Thursday Night

    Thursday Night: Showers likely, mainly after 3am. Mostly cloudy, with a low around 59. Chance of precipitation is 60%.

    Low: 59 °F

    Chance
    Showers then
    Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 68. Chance of precipitation is 80%.

    High: 68 °F

    Heavy Rain

  • Friday Night

    Friday Night: Rain. Low around 53. Chance of precipitation is 80%.

    Low: 53 °F

    Rain

  • Saturday

    Saturday: A 50 percent chance of rain. Partly sunny, with a high near 64.

    High: 64 °F

    Chance Rain

Detailed Forecast

Today
Sunny, with a high near 69. Light southwest wind increasing to 5 to 10 mph in the morning.
Tonight
Mostly clear, with a low around 52. South wind 3 to 6 mph.
Wednesday
Mostly sunny, with a high near 72. Calm wind becoming southwest 5 to 8 mph in the morning.
Wednesday Night
Mostly cloudy, with a low around 56. South wind 3 to 5 mph.
Thursday
A 20 percent chance of showers after 9am. Mostly cloudy, with a high near 70. South wind 5 to 10 mph.
Thursday Night
Showers likely, mainly after 3am. Mostly cloudy, with a low around 59. Chance of precipitation is 60%.
Friday
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 68. Chance of precipitation is 80%.
Friday Night
Rain. Low around 53. Chance of precipitation is 80%.
Saturday
A 50 percent chance of rain. Partly sunny, with a high near 64.
Saturday Night
Partly cloudy, with a low around 45.
Sunday
Mostly sunny, with a high near 60.
Sunday Night
Partly cloudy, with a low around 45.
Monday
A 30 percent chance of rain. Partly sunny, with a high near 59.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.86°N 73.22°W (Elev. 82 ft)
Last Update:
5:22 am EST Nov 3, 2026
Forecast Valid:
7am EST Nov 3, 2026-6pm EST Nov 9, 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