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.

Partly Cloudy

39°F

4°C

Humidity 39%
Wind Speed Calm
Barometer 30.13 in (1020.4 mb)
Dewpoint 16°F (-9°C)
Visibility 10.00 mi
Last update 27 Feb 10:56 am EST
Extended Forecast for

Brentwood NY

  • Today

    Today: Sunny, with a high near 41. Calm wind becoming south around 5 mph.

    High: 41 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 29. Light south wind.

    Low: 29 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 48. Calm wind becoming southwest 5 to 7 mph in the morning.

    High: 48 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 30. Light and variable wind.

    Low: 30 °F

    Mostly Cloudy

  • Sunday

    Sunday: Scattered snow showers before 1pm. Cloudy through mid morning, then gradual clearing, with a high near 38. Northwest wind 6 to 11 mph. Chance of precipitation is 40%.

    High: 38 °F

    Scattered
    Snow Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 17.

    Low: 17 °F

    Partly Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 28.

    High: 28 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 20.

    Low: 20 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A chance of rain and snow after 1pm. Mostly cloudy, with a high near 38. Chance of precipitation is 30%.

    High: 38 °F

    Mostly Cloudy
    then Chance
    Rain/Snow

Detailed Forecast

Today
Sunny, with a high near 41. Calm wind becoming south around 5 mph.
Tonight
Mostly clear, with a low around 29. Light south wind.
Saturday
Mostly sunny, with a high near 48. Calm wind becoming southwest 5 to 7 mph in the morning.
Saturday Night
Mostly cloudy, with a low around 30. Light and variable wind.
Sunday
Scattered snow showers before 1pm. Cloudy through mid morning, then gradual clearing, with a high near 38. Northwest wind 6 to 11 mph. Chance of precipitation is 40%.
Sunday Night
Partly cloudy, with a low around 17.
Monday
Mostly cloudy, with a high near 28.
Monday Night
Mostly cloudy, with a low around 20.
Tuesday
A chance of rain and snow after 1pm. Mostly cloudy, with a high near 38. Chance of precipitation is 30%.
Tuesday Night
Rain likely. Cloudy, with a low around 30. Chance of precipitation is 70%.
Wednesday
A 30 percent chance of rain. Partly sunny, with a high near 44.
Wednesday Night
Mostly cloudy, with a low around 32.
Thursday
Mostly cloudy, with a high near 45.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Brentwood NY
 40.78°N 73.24°W (Elev. 66 ft)
Last Update:
12:50 am EST Feb 27, 2026
Forecast Valid:
11am EST Feb 27, 2026-6pm EST Mar 5, 2026
 
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