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.

Light Rain

76°F

24°C

Humidity 67%
Wind Speed W 9 G 24 mph
Barometer 29.86 in (1011.2 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 14 Oct 12:56 pm EDT
Extended Forecast for

Brentwood NY

  • This Afternoon

    This Afternoon: A chance of showers and thunderstorms before 2pm, then a slight chance of showers between 2pm and 3pm. Partly sunny, with a high near 79. West wind around 9 mph. Chance of precipitation is 30%.

    High: 79 °F

    Chance
    Showers

  • Tonight

    Tonight: Partly cloudy, with a low around 52. North wind around 8 mph.

    Low: 52 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 63. North wind 6 to 9 mph.

    High: 63 °F

    Sunny

  • Thursday Night

    Thursday Night: Showers after 2am. Low around 51. Southeast wind 3 to 7 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 51 °F

    Mostly Clear
    then Showers

  • Friday

    Friday: Showers, with thunderstorms also possible after 5pm. High near 72. Southwest wind 11 to 14 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 72 °F

    Showers

  • Friday Night

    Friday Night: Showers likely before 2am. Cloudy, then gradually becoming partly cloudy, with a low around 44. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 44 °F

    Showers
    Likely

  • Saturday

    Saturday: Sunny, with a high near 54. Breezy.

    High: 54 °F

    Sunny and
    Breezy

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 39.

    Low: 39 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 59.

    High: 59 °F

    Sunny

Detailed Forecast

This Afternoon
A chance of showers and thunderstorms before 2pm, then a slight chance of showers between 2pm and 3pm. Partly sunny, with a high near 79. West wind around 9 mph. Chance of precipitation is 30%.
Tonight
Partly cloudy, with a low around 52. North wind around 8 mph.
Thursday
Sunny, with a high near 63. North wind 6 to 9 mph.
Thursday Night
Showers after 2am. Low around 51. Southeast wind 3 to 7 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Friday
Showers, with thunderstorms also possible after 5pm. High near 72. Southwest wind 11 to 14 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Friday Night
Showers likely before 2am. Cloudy, then gradually becoming partly cloudy, with a low around 44. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
Sunny, with a high near 54. Breezy.
Saturday Night
Mostly clear, with a low around 39.
Sunday
Sunny, with a high near 59.
Sunday Night
Mostly clear, with a low around 44.
Monday
Sunny, with a high near 63.
Monday Night
Partly cloudy, with a low around 48.
Tuesday
Partly sunny, with a high near 66.
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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:
12:51 pm EDT Oct 14, 2026
Forecast Valid:
1pm EDT Oct 14, 2026-6pm EDT Oct 20, 2026
 
Forecast Discussion
 
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Additional Resources

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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