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.

A Few Clouds

36°F

2°C

Humidity 64%
Wind Speed S 7 mph
Barometer 30.12 in (1019.9 mb)
Dewpoint 25°F (-4°C)
Visibility 10.00 mi
Wind Chill30°F (-1°C)
Last update 27 Feb 4:56 pm EST
Extended Forecast for

Brentwood NY

  • Tonight

    Tonight: Patchy fog after 11pm. Otherwise, mostly clear, with a low around 29. Calm wind.

    Low: 29 °F

    Patchy Fog

  • Saturday

    Saturday: Patchy fog before 9am. Otherwise, mostly sunny, with a high near 45. Calm wind becoming southwest around 6 mph.

    High: 45 °F

    Patchy Fog
    then Mostly
    Sunny

  • Saturday Night

    Saturday Night: Patchy fog between 10pm and 2am. Otherwise, partly cloudy, with a low around 29. Calm wind.

    Low: 29 °F

    Patchy Fog

  • Sunday

    Sunday: A slight chance of rain and snow showers before 10am, then snow showers likely. Cloudy, then gradually becoming mostly sunny, with a high near 39. Northwest wind 3 to 8 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.

    High: 39 °F

    Rain/Snow
    Likely then
    Snow Showers
    Likely

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 17. North wind around 7 mph.

    Low: 17 °F

    Mostly Clear

  • Monday

    Monday: Partly sunny, with a high near 29.

    High: 29 °F

    Partly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 20.

    Low: 20 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 41. Chance of precipitation is 50%.

    High: 41 °F

    Chance
    Rain/Snow

  • Tuesday Night

    Tuesday Night: Rain likely. Cloudy, with a low around 35. Chance of precipitation is 70%.

    Low: 35 °F

    Rain Likely

Detailed Forecast

Tonight
Patchy fog after 11pm. Otherwise, mostly clear, with a low around 29. Calm wind.
Saturday
Patchy fog before 9am. Otherwise, mostly sunny, with a high near 45. Calm wind becoming southwest around 6 mph.
Saturday Night
Patchy fog between 10pm and 2am. Otherwise, partly cloudy, with a low around 29. Calm wind.
Sunday
A slight chance of rain and snow showers before 10am, then snow showers likely. Cloudy, then gradually becoming mostly sunny, with a high near 39. Northwest wind 3 to 8 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Sunday Night
Mostly clear, with a low around 17. North wind around 7 mph.
Monday
Partly sunny, with a high near 29.
Monday Night
Partly cloudy, with a low around 20.
Tuesday
A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 41. Chance of precipitation is 50%.
Tuesday Night
Rain likely. Cloudy, with a low around 35. Chance of precipitation is 70%.
Wednesday
A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 46.
Wednesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 34.
Thursday
A 40 percent chance of rain. Cloudy, with a high near 45.
Thursday Night
Rain likely. Cloudy, with a low around 35. Chance of precipitation is 60%.
Friday
A 40 percent chance of rain. Cloudy, with a high near 43.
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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:
12:50 pm EST Feb 27, 2026
Forecast Valid:
5pm EST Feb 27, 2026-6pm EST Mar 6, 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