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

N/A

Humidity NA
Wind Speed NW 20 G 33 mph
Barometer 30.01 in
Dewpoint N/A
Visibility 10.00 mi
Last update 12 Jan 2:56 am EST
Extended Forecast for

Brentwood NY

  • Overnight

    Overnight: Mostly clear, with a low around 28. Wind chill values between 20 and 25. Northwest wind around 15 mph, with gusts as high as 32 mph.

    Low: 28 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 41. Wind chill values between 20 and 30. West wind 10 to 13 mph, with gusts as high as 26 mph.

    High: 41 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 30. West wind 6 to 8 mph, with gusts as high as 20 mph.

    Low: 30 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 44. West wind 6 to 10 mph.

    High: 44 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 38. South wind around 8 mph, with gusts as high as 20 mph.

    Low: 38 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, with a high near 47.

    High: 47 °F

    Mostly Cloudy

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers. Cloudy, with a low around 34.

    Low: 34 °F

    Chance
    Showers

  • Thursday

    Thursday: A 40 percent chance of rain. Mostly cloudy, with a high near 43.

    High: 43 °F

    Chance Rain

  • Thursday Night

    Thursday Night: A 50 percent chance of snow. Mostly cloudy, with a low around 22.

    Low: 22 °F

    Chance Snow

Detailed Forecast

Overnight
Mostly clear, with a low around 28. Wind chill values between 20 and 25. Northwest wind around 15 mph, with gusts as high as 32 mph.
Monday
Sunny, with a high near 41. Wind chill values between 20 and 30. West wind 10 to 13 mph, with gusts as high as 26 mph.
Monday Night
Mostly clear, with a low around 30. West wind 6 to 8 mph, with gusts as high as 20 mph.
Tuesday
Mostly sunny, with a high near 44. West wind 6 to 10 mph.
Tuesday Night
Mostly cloudy, with a low around 38. South wind around 8 mph, with gusts as high as 20 mph.
Wednesday
Mostly cloudy, with a high near 47.
Wednesday Night
A 40 percent chance of showers. Cloudy, with a low around 34.
Thursday
A 40 percent chance of rain. Mostly cloudy, with a high near 43.
Thursday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 22.
Friday
A 30 percent chance of snow before 1pm. Partly sunny, with a high near 34.
Friday Night
Partly cloudy, with a low around 24.
Saturday
Mostly sunny, with a high near 40.
Saturday Night
Mostly cloudy, with a low around 27.
Sunday
A 30 percent chance of snow showers. Partly sunny, with a high near 37.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Brentwood NY
 40.78°N 73.24°W (Elev. 66 ft)
Last Update:
1:57 am EST Jan 12, 2026
Forecast Valid:
3am EST Jan 12, 2026-6pm EST Jan 18, 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