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

40°F

4°C

Humidity 63%
Wind Speed NW 15 mph
Barometer 30.13 in (1020.3 mb)
Dewpoint 28°F (-2°C)
Visibility 10.00 mi
Wind Chill32°F (0°C)
Last update 1 Dec 2:56 am EST
Extended Forecast for

Brentwood NY

  • Overnight

    Overnight: Mostly clear, with a low around 33. West wind around 10 mph, with gusts as high as 23 mph.

    Low: 33 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 42. North wind 7 to 11 mph, with gusts as high as 22 mph.

    High: 42 °F

    Sunny

  • Monday Night

    Monday Night: A 20 percent chance of rain after 4am. Increasing clouds, with a low around 28. Light east wind.

    Low: 28 °F

    Partly Cloudy
    then Slight
    Chance Rain

  • Tuesday

    Tuesday: Rain, mainly after 7am. High near 46. East wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.

    High: 46 °F

    Rain

  • Tuesday Night

    Tuesday Night: A 40 percent chance of rain before 1am. Cloudy, then gradually becoming partly cloudy, with a low around 29. Northwest wind around 10 mph, with gusts as high as 28 mph.

    Low: 29 °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 30.

    Low: 30 °F

    Partly Cloudy

  • Thursday

    Thursday: Partly sunny, with a high near 42.

    High: 42 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 19.

    Low: 19 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 33. West wind around 10 mph, with gusts as high as 23 mph.
Monday
Sunny, with a high near 42. North wind 7 to 11 mph, with gusts as high as 22 mph.
Monday Night
A 20 percent chance of rain after 4am. Increasing clouds, with a low around 28. Light east wind.
Tuesday
Rain, mainly after 7am. High near 46. East wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.
Tuesday Night
A 40 percent chance of rain before 1am. Cloudy, then gradually becoming partly cloudy, with a low around 29. Northwest wind around 10 mph, with gusts as high as 28 mph.
Wednesday
Sunny, with a high near 40.
Wednesday Night
Partly cloudy, with a low around 30.
Thursday
Partly sunny, with a high near 42.
Thursday Night
Mostly clear, with a low around 19.
Friday
Mostly sunny, with a high near 37.
Friday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 27.
Saturday
A chance of rain and snow. Mostly cloudy, with a high near 41. Chance of precipitation is 50%.
Saturday Night
A chance of rain and snow showers. Mostly cloudy, with a low around 30. Chance of precipitation is 30%.
Sunday
Partly sunny, with a high near 42.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Brentwood NY
 40.8°N 73.23°W (Elev. 98 ft)
Last Update:
1:19 am EST Dec 1, 2025
Forecast Valid:
3am EST Dec 1, 2025-6pm EST Dec 7, 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