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

44°F

7°C

Humidity 65%
Wind Speed S 12 mph
Barometer 30.11 in (1019.6 mb)
Dewpoint 33°F (1°C)
Visibility 10.00 mi
Wind Chill38°F (3°C)
Last update 20 Mar 9:56 am EDT
Extended Forecast for

Brentwood NY

  • Today

    Today: A 30 percent chance of rain after 5pm. Partly sunny, with a high near 52. South wind 8 to 14 mph.

    High: 52 °F

    Mostly Sunny
    then Chance
    Rain

  • Tonight

    Tonight: Rain, mainly before 2am. Low around 42. Southwest wind 7 to 13 mph, with gusts as high as 29 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 42 °F

    Rain

  • Saturday

    Saturday: Sunny, with a high near 53. North wind around 8 mph.

    High: 53 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 38. Light and variable wind.

    Low: 38 °F

    Mostly Cloudy

  • Sunday

    Sunday: A 20 percent chance of rain after 2pm. Mostly cloudy, with a high near 53. South wind 5 to 10 mph.

    High: 53 °F

    Mostly Cloudy
    then Slight
    Chance Rain

  • Sunday Night

    Sunday Night: Rain likely, mainly after 2am. Cloudy, with a low around 40. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 40 °F

    Rain Likely

  • Monday

    Monday: Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 48. Chance of precipitation is 60%.

    High: 48 °F

    Rain Likely

  • Monday Night

    Monday Night: Partly cloudy, with a low around 29.

    Low: 29 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 44.

    High: 44 °F

    Sunny

Detailed Forecast

Today
A 30 percent chance of rain after 5pm. Partly sunny, with a high near 52. South wind 8 to 14 mph.
Tonight
Rain, mainly before 2am. Low around 42. Southwest wind 7 to 13 mph, with gusts as high as 29 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
Sunny, with a high near 53. North wind around 8 mph.
Saturday Night
Mostly cloudy, with a low around 38. Light and variable wind.
Sunday
A 20 percent chance of rain after 2pm. Mostly cloudy, with a high near 53. South wind 5 to 10 mph.
Sunday Night
Rain likely, mainly after 2am. Cloudy, with a low around 40. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Monday
Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 48. Chance of precipitation is 60%.
Monday Night
Partly cloudy, with a low around 29.
Tuesday
Sunny, with a high near 44.
Tuesday Night
Mostly cloudy, with a low around 33.
Wednesday
Partly sunny, with a high near 49.
Wednesday Night
Mostly cloudy, with a low around 32.
Thursday
A 30 percent chance of rain. Partly sunny, with a high near 49.
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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:
9:59 am EDT Mar 20, 2026
Forecast Valid:
10am EDT Mar 20, 2026-6pm EDT Mar 26, 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