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.

Overcast

36°F

2°C

Humidity 97%
Wind Speed W 3 mph
Barometer 30.19 in (1022.4 mb)
Dewpoint 35°F (2°C)
Visibility 7.00 mi
Last update 4 Mar 4:56 am EST
Extended Forecast for

Brentwood NY

  • Today

    Today: Patchy fog before 9am. Otherwise, partly sunny, with a high near 45. Calm wind.

    High: 45 °F

    Patchy Fog
    then Partly
    Sunny

  • Tonight

    Tonight: A 30 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, mostly cloudy, with a low around 33. Calm wind.

    Low: 33 °F

    Patchy Fog
    then Chance
    Rain and
    Patchy Fog

  • Thursday

    Thursday: Rain, mainly after 7am. Patchy fog before 10am. High near 41. Calm wind becoming northeast around 6 mph in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    High: 41 °F

    Rain and
    Patchy Fog

  • Thursday Night

    Thursday Night: Rain. Low around 34. Northeast wind 8 to 10 mph. Chance of precipitation is 90%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 34 °F

    Rain

  • Friday

    Friday: A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 42. Northeast wind 6 to 9 mph, with gusts as high as 20 mph.

    High: 42 °F

    Chance Rain

  • Friday Night

    Friday Night: Cloudy, with a low around 35.

    Low: 35 °F

    Cloudy

  • Saturday

    Saturday: Cloudy, with a high near 51.

    High: 51 °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

Today
Patchy fog before 9am. Otherwise, partly sunny, with a high near 45. Calm wind.
Tonight
A 30 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, mostly cloudy, with a low around 33. Calm wind.
Thursday
Rain, mainly after 7am. Patchy fog before 10am. High near 41. Calm wind becoming northeast around 6 mph in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Rain. Low around 34. Northeast wind 8 to 10 mph. Chance of precipitation is 90%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 42. Northeast wind 6 to 9 mph, with gusts as high as 20 mph.
Friday Night
Cloudy, with a low around 35.
Saturday
Cloudy, with a high near 51.
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 41.
Monday
Sunny, with a high near 56.
Monday Night
Mostly clear, with a low around 41.
Tuesday
Mostly sunny, with a high near 56.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Brentwood NY
 40.78°N 73.24°W (Elev. 66 ft)
Last Update:
6:26 am EST Mar 4, 2026
Forecast Valid:
6am EST Mar 4, 2026-6pm EDT Mar 10, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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