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

46°F

8°C

Humidity 86%
Wind Speed SW 16 G 23 mph
Barometer 30.23 in (1023.6 mb)
Dewpoint 42°F (6°C)
Visibility 10.00 mi
Wind Chill39°F (4°C)
Last update 30 Mar 7:56 am EDT
Extended Forecast for

Brentwood NY

  • Today

    Today: A 20 percent chance of showers after 2pm. Partly sunny, with a high near 59. Southwest wind 13 to 16 mph, with gusts as high as 30 mph.

    High: 59 °F

    Partly Sunny
    then Slight
    Chance
    Showers

  • Tonight

    Tonight: Showers likely, mainly after 5am. Mostly cloudy, with a low around 47. Southwest wind 8 to 10 mph, with gusts as high as 23 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 47 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely, mainly before 8am. Mostly cloudy, with a high near 63. Southwest wind 9 to 14 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    High: 63 °F

    Showers
    Likely then
    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 51. South wind around 14 mph, with gusts as high as 26 mph.

    Low: 51 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm, mainly after 5pm. Partly sunny, with a high near 67. Southwest wind 13 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 67 °F

    Mostly Sunny
    then Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 45. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 45 °F

    Showers
    Likely

  • Thursday

    Thursday: A 30 percent chance of showers before 2pm. Mostly cloudy, with a high near 53.

    High: 53 °F

    Chance
    Showers

  • Thursday Night

    Thursday Night: A 30 percent chance of rain. Cloudy, with a low around 42.

    Low: 42 °F

    Chance Rain

  • Friday

    Friday: Cloudy, with a high near 59.

    High: 59 °F

    Cloudy

Detailed Forecast

Today
A 20 percent chance of showers after 2pm. Partly sunny, with a high near 59. Southwest wind 13 to 16 mph, with gusts as high as 30 mph.
Tonight
Showers likely, mainly after 5am. Mostly cloudy, with a low around 47. Southwest wind 8 to 10 mph, with gusts as high as 23 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday
Showers likely, mainly before 8am. Mostly cloudy, with a high near 63. Southwest wind 9 to 14 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday Night
Mostly cloudy, with a low around 51. South wind around 14 mph, with gusts as high as 26 mph.
Wednesday
Showers likely and possibly a thunderstorm, mainly after 5pm. Partly sunny, with a high near 67. Southwest wind 13 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
Showers likely before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 45. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday
A 30 percent chance of showers before 2pm. Mostly cloudy, with a high near 53.
Thursday Night
A 30 percent chance of rain. Cloudy, with a low around 42.
Friday
Cloudy, with a high near 59.
Friday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 48.
Saturday
A 30 percent chance of rain. Mostly cloudy, with a high near 59.
Saturday Night
A 40 percent chance of rain. Cloudy, with a low around 43.
Sunday
A 50 percent chance of rain. Cloudy, with a high near 59.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Brentwood NY
 40.78°N 73.24°W (Elev. 66 ft)
Last Update:
5:34 am EDT Mar 30, 2026
Forecast Valid:
8am EDT Mar 30, 2026-6pm EDT Apr 5, 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