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

64°F

18°C

Humidity 50%
Wind Speed SW 9 G 22 mph
Barometer 29.95 in (1014.2 mb)
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Last update 7 Oct 2:56 pm EDT
Extended Forecast for

Smithtown NY

  • Tonight

    Tonight: Mostly clear, with a low around 58. Southwest wind around 11 mph.

    Low: 58 °F

    Mostly Clear

  • Thursday

    Thursday: Partly sunny, then gradually becoming sunny, with a high near 73. Southwest wind 9 to 13 mph becoming west in the afternoon.

    High: 73 °F

    Becoming
    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 53. Northwest wind around 6 mph.

    Low: 53 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 69. West wind 7 to 10 mph.

    High: 69 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 51. Northwest wind around 6 mph becoming calm in the evening.

    Low: 51 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 68.

    High: 68 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 57.

    Low: 57 °F

    Partly Cloudy

  • Sunday

    Sunday: Showers. High near 68. Chance of precipitation is 90%.

    High: 68 °F

    Showers

  • Sunday Night

    Sunday Night: Showers. Low around 61. Chance of precipitation is 80%.

    Low: 61 °F

    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 58. Southwest wind around 11 mph.
Thursday
Partly sunny, then gradually becoming sunny, with a high near 73. Southwest wind 9 to 13 mph becoming west in the afternoon.
Thursday Night
Mostly clear, with a low around 53. Northwest wind around 6 mph.
Friday
Sunny, with a high near 69. West wind 7 to 10 mph.
Friday Night
Mostly clear, with a low around 51. Northwest wind around 6 mph becoming calm in the evening.
Saturday
Sunny, with a high near 68.
Saturday Night
Partly cloudy, with a low around 57.
Sunday
Showers. High near 68. Chance of precipitation is 90%.
Sunday Night
Showers. Low around 61. Chance of precipitation is 80%.
Columbus Day
Showers likely, mainly before 8am. Mostly cloudy, with a high near 70. Chance of precipitation is 60%.
Monday Night
Mostly cloudy, with a low around 58.
Tuesday
A 30 percent chance of showers. Partly sunny, with a high near 66.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 48.
Wednesday
Mostly sunny, with a high near 59.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.88°N 73.21°W (Elev. 85 ft)
Last Update:
2:28 pm EDT Oct 7, 2026
Forecast Valid:
3pm EDT Oct 7, 2026-6pm EDT Oct 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