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

39°F

4°C

Humidity 73%
Wind Speed Calm
Barometer 30.11 in (1019.5 mb)
Dewpoint 31°F (-1°C)
Visibility 10.00 mi
Last update 7 Dec 8:56 am EST
Extended Forecast for

Sayville NY

  • Today

    Today: Partly sunny, with a high near 42. Light and variable wind becoming southwest 5 to 8 mph in the morning.

    High: 42 °F

    Partly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 25. Wind chill values between 15 and 20. West wind 8 to 16 mph, with gusts as high as 28 mph.

    Low: 25 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 31. Wind chill values between 15 and 20. North wind 14 to 18 mph, with gusts as high as 31 mph.

    High: 31 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 17. Wind chill values between 10 and 15. North wind 6 to 10 mph, with gusts as high as 20 mph.

    Low: 17 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Increasing clouds, with a high near 41. Light and variable wind becoming southwest 8 to 13 mph in the morning.

    High: 41 °F

    Increasing
    Clouds

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 33.

    Low: 33 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 40 percent chance of rain. Mostly cloudy, with a high near 49.

    High: 49 °F

    Chance Rain

  • Wednesday Night

    Wednesday Night: A 30 percent chance of rain before 1am. Mostly cloudy, with a low around 35.

    Low: 35 °F

    Chance Rain

  • Thursday

    Thursday: Mostly sunny, with a high near 43.

    High: 43 °F

    Mostly Sunny

Detailed Forecast

Today
Partly sunny, with a high near 42. Light and variable wind becoming southwest 5 to 8 mph in the morning.
Tonight
Partly cloudy, with a low around 25. Wind chill values between 15 and 20. West wind 8 to 16 mph, with gusts as high as 28 mph.
Monday
Mostly sunny, with a high near 31. Wind chill values between 15 and 20. North wind 14 to 18 mph, with gusts as high as 31 mph.
Monday Night
Partly cloudy, with a low around 17. Wind chill values between 10 and 15. North wind 6 to 10 mph, with gusts as high as 20 mph.
Tuesday
Increasing clouds, with a high near 41. Light and variable wind becoming southwest 8 to 13 mph in the morning.
Tuesday Night
Mostly cloudy, with a low around 33.
Wednesday
A 40 percent chance of rain. Mostly cloudy, with a high near 49.
Wednesday Night
A 30 percent chance of rain before 1am. Mostly cloudy, with a low around 35.
Thursday
Mostly sunny, with a high near 43.
Thursday Night
A chance of rain and snow after 1am. Mostly cloudy, with a low around 31. Chance of precipitation is 30%.
Friday
A chance of rain and snow. Mostly cloudy, with a high near 40. Chance of precipitation is 40%.
Friday Night
A chance of rain and snow. Mostly cloudy, with a low around 25. Chance of precipitation is 40%.
Saturday
A 30 percent chance of snow. Partly sunny, with a high near 35.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sayville NY
 40.73°N 73.07°W (Elev. 16 ft)
Last Update:
7:42 am EST Dec 7, 2025
Forecast Valid:
9am EST Dec 7, 2025-6pm EST Dec 13, 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