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.

Mostly Cloudy

69°F

21°C

Humidity 70%
Wind Speed E 14 mph
Barometer 30.10 in (1019.2 mb)
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Last update 16 Jun 4:56 pm EDT
Extended Forecast for

Smithtown NY

  • Tonight

    Tonight: A slight chance of showers between 8pm and midnight, then a slight chance of drizzle or light rain after midnight. Patchy fog after 8pm. Otherwise, cloudy, with a low around 62. East wind 5 to 10 mph. Chance of precipitation is 20%.

    Low: 62 °F

    Slight Chance
    Showers and
    Patchy Fog

  • Tuesday

    Tuesday: A 30 percent chance of showers, mainly after 8am. Patchy fog before noon. Otherwise, cloudy, with a high near 72. East wind 6 to 8 mph.

    High: 72 °F

    Chance
    Showers and
    Patchy Fog

  • Tuesday Night

    Tuesday Night: A chance of showers, with thunderstorms also possible after 2am. Areas of fog. Otherwise, cloudy, with a low around 64. South wind around 6 mph. Chance of precipitation is 50%.

    Low: 64 °F

    Chance
    Showers and
    Areas Fog

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 5pm. Mostly cloudy, with a high near 80. South wind 3 to 7 mph. Chance of precipitation is 40%.

    High: 80 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 67. South wind 3 to 6 mph. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Juneteenth

    Juneteenth: A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A 30 percent chance of showers before 2am. Partly cloudy, with a low around 66.

    Low: 66 °F

    Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

Detailed Forecast

Tonight
A slight chance of showers between 8pm and midnight, then a slight chance of drizzle or light rain after midnight. Patchy fog after 8pm. Otherwise, cloudy, with a low around 62. East wind 5 to 10 mph. Chance of precipitation is 20%.
Tuesday
A 30 percent chance of showers, mainly after 8am. Patchy fog before noon. Otherwise, cloudy, with a high near 72. East wind 6 to 8 mph.
Tuesday Night
A chance of showers, with thunderstorms also possible after 2am. Areas of fog. Otherwise, cloudy, with a low around 64. South wind around 6 mph. Chance of precipitation is 50%.
Wednesday
A chance of showers, with thunderstorms also possible after 5pm. Mostly cloudy, with a high near 80. South wind 3 to 7 mph. Chance of precipitation is 40%.
Wednesday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 67. South wind 3 to 6 mph. Chance of precipitation is 40%.
Juneteenth
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 88.
Thursday Night
A 30 percent chance of showers before 2am. Partly cloudy, with a low around 66.
Friday
Sunny, with a high near 84.
Friday Night
Mostly clear, with a low around 63.
Saturday
Mostly sunny, with a high near 83.
Saturday Night
Mostly cloudy, with a low around 67.
Sunday
Partly sunny, with a high near 85.
Sunday Night
Partly cloudy, with a low around 68.
Monday
Mostly sunny, with a high near 88.
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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:
4:02 pm EDT Jun 16, 2025
Forecast Valid:
5pm EDT Jun 16, 2025-6pm EDT Jun 23, 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