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

56°F

13°C

Humidity 51%
Wind Speed SW 10 mph
Barometer 29.89 in (1012.2 mb)
Dewpoint 38°F (3°C)
Visibility 10.00 mi
Last update 10 Nov 11:56 am EST
Extended Forecast for

Smithtown NY

  • This Afternoon

    This Afternoon: Partly sunny, then gradually becoming sunny, with a high near 60. Southwest wind 10 to 13 mph.

    High: 60 °F

    Becoming
    Sunny

  • Tonight

    Tonight: Clear, with a low around 44. West wind around 8 mph.

    Low: 44 °F

    Clear

  • Veterans Day

    Veterans Day: Increasing clouds, with a high near 60. West wind 3 to 7 mph.

    High: 60 °F

    Increasing
    Clouds

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 44. Calm wind becoming east around 5 mph after midnight.

    Low: 44 °F

    Mostly Cloudy

  • Thursday

    Thursday: Rain likely, mainly after 1pm. Mostly cloudy, with a high near 59. East wind 7 to 13 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 59 °F

    Chance Rain
    then Rain
    Likely

  • Thursday Night

    Thursday Night: Rain. Low around 41. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 41 °F

    Rain

  • Friday

    Friday: Rain. High near 50. Chance of precipitation is 80%.

    High: 50 °F

    Rain

  • Friday Night

    Friday Night: A 40 percent chance of rain. Mostly cloudy, with a low around 35.

    Low: 35 °F

    Chance Rain

  • Saturday

    Saturday: Mostly cloudy, with a high near 49.

    High: 49 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
Partly sunny, then gradually becoming sunny, with a high near 60. Southwest wind 10 to 13 mph.
Tonight
Clear, with a low around 44. West wind around 8 mph.
Veterans Day
Increasing clouds, with a high near 60. West wind 3 to 7 mph.
Wednesday Night
Mostly cloudy, with a low around 44. Calm wind becoming east around 5 mph after midnight.
Thursday
Rain likely, mainly after 1pm. Mostly cloudy, with a high near 59. East wind 7 to 13 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday Night
Rain. Low around 41. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday
Rain. High near 50. Chance of precipitation is 80%.
Friday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 35.
Saturday
Mostly cloudy, with a high near 49.
Saturday Night
Mostly cloudy, with a low around 35.
Sunday
Mostly sunny, with a high near 51.
Sunday Night
Partly cloudy, with a low around 35.
Monday
Mostly sunny, with a high near 52.
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 73.22°W (Elev. 82 ft)
Last Update:
6:01 am EST Nov 10, 2026
Forecast Valid:
12pm EST Nov 10, 2026-6pm EST Nov 16, 2026
 
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