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.

Light Rain

48°F

9°C

Humidity 77%
Wind Speed S 13 mph
Barometer 30.21 in (1023.0 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Wind Chill43°F (6°C)
Last update 30 Nov 11:56 am EST
Extended Forecast for

Smithtown NY

  • This Afternoon

    This Afternoon: Rain, mainly after 1pm. Temperature falling to around 48 by 4pm. South wind 11 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    High: 51 °F⇓

    Rain

  • Tonight

    Tonight: A 40 percent chance of rain before 10pm. Cloudy during the early evening, then gradual clearing, with a low around 33. West wind around 10 mph, with gusts as high as 21 mph.

    Low: 33 °F

    Chance Rain
    then Mostly
    Clear

  • Monday

    Monday: Sunny, with a high near 43. Northwest wind 7 to 11 mph, with gusts as high as 21 mph.

    High: 43 °F

    Sunny

  • Monday Night

    Monday Night: Increasing clouds, with a low around 28. Light and variable wind.

    Low: 28 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Rain. High near 47. Southeast wind 5 to 9 mph becoming north in the afternoon. Chance of precipitation is 100%. New precipitation amounts between three quarters and one inch possible.

    High: 47 °F

    Rain

  • Tuesday Night

    Tuesday Night: A 40 percent chance of rain before 1am. Cloudy during the early evening, then gradual clearing, with a low around 28.

    Low: 28 °F

    Chance Rain

  • Wednesday

    Wednesday: Sunny, with a high near 40.

    High: 40 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 31.

    Low: 31 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 44.

    High: 44 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
Rain, mainly after 1pm. Temperature falling to around 48 by 4pm. South wind 11 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Tonight
A 40 percent chance of rain before 10pm. Cloudy during the early evening, then gradual clearing, with a low around 33. West wind around 10 mph, with gusts as high as 21 mph.
Monday
Sunny, with a high near 43. Northwest wind 7 to 11 mph, with gusts as high as 21 mph.
Monday Night
Increasing clouds, with a low around 28. Light and variable wind.
Tuesday
Rain. High near 47. Southeast wind 5 to 9 mph becoming north in the afternoon. Chance of precipitation is 100%. New precipitation amounts between three quarters and one inch possible.
Tuesday Night
A 40 percent chance of rain before 1am. Cloudy during the early evening, then gradual clearing, with a low around 28.
Wednesday
Sunny, with a high near 40.
Wednesday Night
Partly cloudy, with a low around 31.
Thursday
Mostly cloudy, with a high near 44.
Thursday Night
Partly cloudy, with a low around 19.
Friday
Mostly sunny, with a high near 34.
Friday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 26.
Saturday
A chance of rain and snow. Mostly cloudy, with a high near 39. Chance of precipitation is 50%.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Smithtown NY
 40.86°N 73.19°W (Elev. 98 ft)
Last Update:
6:16 am EST Nov 30, 2025
Forecast Valid:
12pm EST Nov 30, 2025-6pm EST Dec 6, 2025
 
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