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.

Fair

58°F

14°C

Humidity 90%
Wind Speed NE 3 mph
Barometer 29.99 in (1015.6 mb)
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Last update 3 Sep 3:56 am EDT
Extended Forecast for

Brentwood NY

  • Today

    Today: Patchy fog before 8am. Otherwise, mostly sunny, with a high near 76. Calm wind becoming south 5 to 7 mph in the afternoon.

    High: 76 °F

    Patchy Fog
    then Mostly
    Sunny

  • Tonight

    Tonight: Patchy fog after 2am. Otherwise, mostly clear, with a low around 59. South wind around 5 mph becoming calm in the evening.

    Low: 59 °F

    Mostly Clear
    then Patchy
    Fog

  • Thursday

    Thursday: Patchy fog before 8am. Otherwise, sunny, with a high near 77. Light south wind increasing to 8 to 13 mph in the morning.

    High: 77 °F

    Patchy Fog
    then Sunny

  • Thursday Night

    Thursday Night: A chance of showers before 11pm, then a chance of showers and thunderstorms between 11pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 65. South wind 9 to 11 mph. Chance of precipitation is 40%.

    Low: 65 °F

    Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 81. South wind 8 to 15 mph.

    High: 81 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 68.

    Low: 68 °F

    Mostly Clear

  • Saturday

    Saturday: A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 82.

    High: 82 °F

    Mostly Sunny
    then Chance
    Showers

  • Saturday Night

    Saturday Night: Showers likely, mainly between 8pm and 2am. Mostly cloudy, with a low around 60. Chance of precipitation is 60%.

    Low: 60 °F

    Showers
    Likely

  • Sunday

    Sunday: A 30 percent chance of showers before 2pm. Partly sunny, with a high near 75.

    High: 75 °F

    Chance
    Showers

Detailed Forecast

Today
Patchy fog before 8am. Otherwise, mostly sunny, with a high near 76. Calm wind becoming south 5 to 7 mph in the afternoon.
Tonight
Patchy fog after 2am. Otherwise, mostly clear, with a low around 59. South wind around 5 mph becoming calm in the evening.
Thursday
Patchy fog before 8am. Otherwise, sunny, with a high near 77. Light south wind increasing to 8 to 13 mph in the morning.
Thursday Night
A chance of showers before 11pm, then a chance of showers and thunderstorms between 11pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 65. South wind 9 to 11 mph. Chance of precipitation is 40%.
Friday
Sunny, with a high near 81. South wind 8 to 15 mph.
Friday Night
Mostly clear, with a low around 68.
Saturday
A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 82.
Saturday Night
Showers likely, mainly between 8pm and 2am. Mostly cloudy, with a low around 60. Chance of precipitation is 60%.
Sunday
A 30 percent chance of showers before 2pm. Partly sunny, with a high near 75.
Sunday Night
Partly cloudy, with a low around 57.
Monday
Sunny, with a high near 75.
Monday Night
Partly cloudy, with a low around 57.
Tuesday
Mostly sunny, with a high near 74.
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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:
1:52 am EDT Sep 3, 2025
Forecast Valid:
4am EDT Sep 3, 2025-6pm EDT Sep 9, 2025
 
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