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.

Light Drizzle Fog/Mist

68°F

20°C

Humidity 93%
Wind Speed N 13 mph
Barometer 29.99 in (1015.6 mb)
Dewpoint 66°F (19°C)
Visibility 3.00 mi
Last update 7 Jul 3:56 pm EDT
Extended Forecast for

Smithtown NY

  • This Afternoon

    This Afternoon: A 30 percent chance of rain. Cloudy, with a high near 72. North wind around 10 mph.

    High: 72 °F

    Chance Rain

  • Tonight

    Tonight: A 30 percent chance of rain before 8pm. Mostly cloudy, with a low around 63. North wind around 8 mph.

    Low: 63 °F

    Chance Rain
    then Mostly
    Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 79. North wind 5 to 7 mph.

    High: 79 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Increasing clouds, with a low around 67. Southwest wind around 6 mph.

    Low: 67 °F

    Increasing
    Clouds

  • Thursday

    Thursday: Mostly sunny, with a high near 82. Southwest wind 6 to 11 mph.

    High: 82 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 50%.

    Low: 71 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 89.

    High: 89 °F

    Mostly Sunny
    then Chance
    T-storms

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 71.

    Low: 71 °F

    Chance
    T-storms then
    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 30 percent chance of rain. Cloudy, with a high near 72. North wind around 10 mph.
Tonight
A 30 percent chance of rain before 8pm. Mostly cloudy, with a low around 63. North wind around 8 mph.
Wednesday
Mostly sunny, with a high near 79. North wind 5 to 7 mph.
Wednesday Night
Increasing clouds, with a low around 67. Southwest wind around 6 mph.
Thursday
Mostly sunny, with a high near 82. Southwest wind 6 to 11 mph.
Thursday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 50%.
Friday
A 40 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 89.
Friday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 71.
Saturday
Mostly sunny, with a high near 84.
Saturday Night
Partly cloudy, with a low around 68.
Sunday
Sunny, with a high near 85.
Sunday Night
Partly cloudy, with a low around 69.
Monday
Mostly sunny, with a high near 87.
Monday Night
Partly cloudy, with a low around 71.
Tuesday
Sunny, with a high near 92.
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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:
3:01 pm EDT Jul 7, 2026
Forecast Valid:
4pm EDT Jul 7, 2026-6pm EDT Jul 14, 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