National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Heavy Rain Fog/Mist

75°F

24°C

Humidity 96%
Wind Speed W 13 mph
Barometer 29.76 in (1007.7 mb)
Dewpoint 74°F (23°C)
Visibility 1.50 mi
Last update 3 Aug 8:56 am EDT
Extended Forecast for

Smithtown NY

  • Today

    Today: Showers and possibly a thunderstorm. High near 81. Southwest wind around 16 mph, with gusts as high as 26 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 81 °F

    Showers

  • Tonight

    Tonight: A 20 percent chance of showers before 11pm. Cloudy, then gradually becoming partly cloudy, with a low around 65. West wind 6 to 8 mph becoming north after midnight.

    Low: 65 °F

    Slight Chance
    Showers then
    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 83. North wind around 6 mph becoming east in the afternoon.

    High: 83 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 66. South wind around 5 mph becoming calm in the evening.

    Low: 66 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon. Chance of precipitation is 40%.

    High: 83 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 71.

    Low: 71 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A chance of showers between 8pm and 2am. Partly cloudy, with a low around 73. Chance of precipitation is 30%.

    Low: 73 °F

    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny

Detailed Forecast

Today
Showers and possibly a thunderstorm. High near 81. Southwest wind around 16 mph, with gusts as high as 26 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Tonight
A 20 percent chance of showers before 11pm. Cloudy, then gradually becoming partly cloudy, with a low around 65. West wind 6 to 8 mph becoming north after midnight.
Tuesday
Mostly sunny, with a high near 83. North wind around 6 mph becoming east in the afternoon.
Tuesday Night
Mostly cloudy, with a low around 66. South wind around 5 mph becoming calm in the evening.
Wednesday
A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon. Chance of precipitation is 40%.
Wednesday Night
Mostly cloudy, with a low around 71.
Thursday
Mostly sunny, with a high near 86.
Thursday Night
A chance of showers between 8pm and 2am. Partly cloudy, with a low around 73. Chance of precipitation is 30%.
Friday
Mostly sunny, with a high near 88.
Friday Night
A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 73. Chance of precipitation is 40%.
Saturday
A 30 percent chance of showers. Mostly sunny, with a high near 87.
Saturday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 71.
Sunday
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 73.22°W (Elev. 82 ft)
Last Update:
2:12 am EDT Aug 3, 2026
Forecast Valid:
9am EDT Aug 3, 2026-6pm EDT Aug 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