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 68%
Wind Speed NE 7 mph
Barometer 30.25 in (1024.3 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Wind Chill40°F (4°C)
Last update 4 Mar 12:56 pm EST
Extended Forecast for

Brentwood NY

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 45. Calm wind.

    High: 45 °F

    Partly Sunny

  • Tonight

    Tonight: A 40 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, mostly cloudy, with a low around 32. Calm wind.

    Low: 32 °F

    Patchy Fog
    then Chance
    Rain and
    Patchy Fog

  • Thursday

    Thursday: Rain, mainly after 7am. Areas of fog before 1pm. High near 40. Calm wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 40 °F

    Rain and
    Areas Fog

  • Thursday Night

    Thursday Night: Rain. Steady temperature around 37. Northeast wind 7 to 9 mph, with gusts as high as 21 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 37 °F

    Rain

  • Friday

    Friday: A 30 percent chance of rain before 1pm. Cloudy, with a high near 42. Northeast wind 6 to 9 mph.

    High: 42 °F

    Chance Rain

  • Friday Night

    Friday Night: Cloudy, with a low around 34.

    Low: 34 °F

    Cloudy

  • Saturday

    Saturday: Cloudy, with a high near 50.

    High: 50 °F

    Cloudy

  • Saturday Night

    Saturday Night: Showers likely, mainly before 1am. Cloudy, with a low around 41. Chance of precipitation is 60%.

    Low: 41 °F

    Showers
    Likely

  • Sunday

    Sunday: Partly sunny, with a high near 54.

    High: 54 °F

    Partly Sunny

Detailed Forecast

This Afternoon
Partly sunny, with a high near 45. Calm wind.
Tonight
A 40 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, mostly cloudy, with a low around 32. Calm wind.
Thursday
Rain, mainly after 7am. Areas of fog before 1pm. High near 40. Calm wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Rain. Steady temperature around 37. Northeast wind 7 to 9 mph, with gusts as high as 21 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
A 30 percent chance of rain before 1pm. Cloudy, with a high near 42. Northeast wind 6 to 9 mph.
Friday Night
Cloudy, with a low around 34.
Saturday
Cloudy, with a high near 50.
Saturday Night
Showers likely, mainly before 1am. Cloudy, with a low around 41. Chance of precipitation is 60%.
Sunday
Partly sunny, with a high near 54.
Sunday Night
Partly cloudy, with a low around 39.
Monday
Mostly sunny, with a high near 52.
Monday Night
Partly cloudy, with a low around 41.
Tuesday
Partly sunny, with a high near 56.
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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:
1:01 pm EST Mar 4, 2026
Forecast Valid:
1pm EST Mar 4, 2026-6pm EDT Mar 10, 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