National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

23°F

-5°C

Humidity 85%
Wind Speed Calm
Barometer 30.21 in (1023.0 mb)
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Last update 28 Dec 7:56 am EST
Extended Forecast for

Brentwood NY

  • Today

    Today: A 20 percent chance of rain after 4pm. Increasing clouds, with a high near 38. Wind chill values between 15 and 25. Northwest wind 5 to 7 mph becoming southwest in the afternoon.

    High: 38 °F

    Mostly Sunny
    then Slight
    Chance Rain

  • Tonight

    Tonight: Rain, mainly before 4am. Temperature rising to around 43 by 4am. Southwest wind 6 to 11 mph, with gusts as high as 22 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 33 °F⇑

    Rain

  • Monday

    Monday: Rain, mainly after 7am. High near 51. Southwest wind 10 to 14 mph, with gusts as high as 29 mph. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch possible.

    High: 51 °F

    Rain

  • Monday Night

    Monday Night: Mostly cloudy during the early evening, then becoming mostly clear, with a low around 25. Wind chill values between 15 and 20. West wind around 16 mph, with gusts as high as 33 mph.

    Low: 25 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 33. Breezy, with a west wind 16 to 20 mph, with gusts as high as 37 mph.

    High: 33 °F

    Mostly Cloudy
    and Breezy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 25.

    Low: 25 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 36.

    High: 36 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 24.

    Low: 24 °F

    Mostly Cloudy

  • New Year's Day

    New Year's Day: A 30 percent chance of snow after 1pm. Partly sunny, with a high near 33.

    High: 33 °F

    Partly Sunny
    then Chance
    Snow

Detailed Forecast

Today
A 20 percent chance of rain after 4pm. Increasing clouds, with a high near 38. Wind chill values between 15 and 25. Northwest wind 5 to 7 mph becoming southwest in the afternoon.
Tonight
Rain, mainly before 4am. Temperature rising to around 43 by 4am. Southwest wind 6 to 11 mph, with gusts as high as 22 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday
Rain, mainly after 7am. High near 51. Southwest wind 10 to 14 mph, with gusts as high as 29 mph. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch possible.
Monday Night
Mostly cloudy during the early evening, then becoming mostly clear, with a low around 25. Wind chill values between 15 and 20. West wind around 16 mph, with gusts as high as 33 mph.
Tuesday
Mostly cloudy, with a high near 33. Breezy, with a west wind 16 to 20 mph, with gusts as high as 37 mph.
Tuesday Night
Mostly cloudy, with a low around 25.
Wednesday
Mostly sunny, with a high near 36.
Wednesday Night
Mostly cloudy, with a low around 24.
New Year's Day
A 30 percent chance of snow after 1pm. Partly sunny, with a high near 33.
Thursday Night
Mostly cloudy, with a low around 20.
Friday
Mostly sunny, with a high near 31.
Friday Night
Partly cloudy, with a low around 20.
Saturday
Mostly sunny, with a high near 37.
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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:
1:17 am EST Dec 28, 2025
Forecast Valid:
8am EST Dec 28, 2025-6pm EST Jan 3, 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