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.

Fair

35°F

2°C

Humidity 52%
Wind Speed W 12 mph
Barometer 30.17 in (1021.6 mb)
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Wind Chill27°F (-3°C)
Last update 29 Nov 12:56 am EST
Extended Forecast for

Smithtown NY

  • Overnight

    Overnight: Mostly clear, with a low around 31. Wind chill values between 25 and 30. West wind around 10 mph, with gusts as high as 24 mph.

    Low: 31 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 42. Wind chill values between 20 and 30. Northwest wind 6 to 10 mph, with gusts as high as 20 mph.

    High: 42 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 30. Light and variable wind.

    Low: 30 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Rain, mainly after 1pm. High near 52. South wind 6 to 14 mph, with gusts as high as 28 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    High: 52 °F

    Chance Rain
    then Rain

  • Sunday Night

    Sunday Night: A 40 percent chance of rain before 1am. Cloudy during the early evening, then gradual clearing, with a low around 33. Southwest wind 10 to 13 mph, with gusts as high as 24 mph.

    Low: 33 °F

    Chance Rain

  • Monday

    Monday: Sunny, with a high near 41.

    High: 41 °F

    Sunny

  • Monday Night

    Monday Night: Increasing clouds, with a low around 28.

    Low: 28 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Rain, mainly after 1pm. High near 47. Chance of precipitation is 90%.

    High: 47 °F

    Chance Rain
    then Rain

  • Tuesday Night

    Tuesday Night: Rain likely, mainly before 1am. Mostly cloudy, with a low around 30. Chance of precipitation is 70%.

    Low: 30 °F

    Rain Likely

Detailed Forecast

Overnight
Mostly clear, with a low around 31. Wind chill values between 25 and 30. West wind around 10 mph, with gusts as high as 24 mph.
Saturday
Sunny, with a high near 42. Wind chill values between 20 and 30. Northwest wind 6 to 10 mph, with gusts as high as 20 mph.
Saturday Night
Increasing clouds, with a low around 30. Light and variable wind.
Sunday
Rain, mainly after 1pm. High near 52. South wind 6 to 14 mph, with gusts as high as 28 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Sunday Night
A 40 percent chance of rain before 1am. Cloudy during the early evening, then gradual clearing, with a low around 33. Southwest wind 10 to 13 mph, with gusts as high as 24 mph.
Monday
Sunny, with a high near 41.
Monday Night
Increasing clouds, with a low around 28.
Tuesday
Rain, mainly after 1pm. High near 47. Chance of precipitation is 90%.
Tuesday Night
Rain likely, mainly before 1am. Mostly cloudy, with a low around 30. Chance of precipitation is 70%.
Wednesday
Mostly sunny, with a high near 41.
Wednesday Night
Partly cloudy, with a low around 29.
Thursday
Partly sunny, with a high near 41.
Thursday Night
Partly cloudy, with a low around 21.
Friday
Partly sunny, with a high near 37.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.86°N 73.19°W (Elev. 98 ft)
Last Update:
1:05 am EST Nov 29, 2025
Forecast Valid:
1am EST Nov 29, 2025-6pm EST Dec 5, 2025
 
Forecast Discussion
 
Get as KML Get as XML

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