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

70°F

21°C

Humidity 64%
Wind Speed NW 14 G 22 mph
Barometer 29.77 in (1008.1 mb)
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Last update 12 Oct 1:56 pm EDT
Extended Forecast for

Smithtown NY

  • Columbus Day

    Columbus Day: Sunny, with a high near 70. Northwest wind around 7 mph.

    High: 70 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 56. Light north wind.

    Low: 56 °F

    Mostly Clear

  • Tuesday

    Tuesday: Increasing clouds, with a high near 70. Calm wind becoming south 5 to 9 mph in the morning.

    High: 70 °F

    Increasing
    Clouds

  • Tuesday Night

    Tuesday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 62. Southwest wind around 9 mph, with gusts as high as 20 mph.

    Low: 62 °F

    Decreasing
    Clouds

  • Wednesday

    Wednesday: Mostly sunny, with a high near 76. West wind around 9 mph.

    High: 76 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 56.

    Low: 56 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 66.

    High: 66 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Showers likely after 2am. Partly cloudy, with a low around 53. Chance of precipitation is 60%.

    Low: 53 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers. High near 69. Chance of precipitation is 80%.

    High: 69 °F

    Showers

Detailed Forecast

Columbus Day
Sunny, with a high near 70. Northwest wind around 7 mph.
Tonight
Mostly clear, with a low around 56. Light north wind.
Tuesday
Increasing clouds, with a high near 70. Calm wind becoming south 5 to 9 mph in the morning.
Tuesday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 62. Southwest wind around 9 mph, with gusts as high as 20 mph.
Wednesday
Mostly sunny, with a high near 76. West wind around 9 mph.
Wednesday Night
Mostly cloudy, with a low around 56.
Thursday
Mostly sunny, with a high near 66.
Thursday Night
Showers likely after 2am. Partly cloudy, with a low around 53. Chance of precipitation is 60%.
Friday
Showers. High near 69. Chance of precipitation is 80%.
Friday Night
Showers likely, mainly before 8pm. Mostly cloudy, with a low around 45. Breezy. Chance of precipitation is 60%.
Saturday
Mostly sunny, with a high near 54. Breezy.
Saturday Night
Mostly clear, with a low around 39.
Sunday
Sunny, with a high near 55.
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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:
6:26 am EDT Oct 12, 2026
Forecast Valid:
2pm EDT Oct 12, 2026-6pm EDT Oct 18, 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