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.

Partly Cloudy

34°F

1°C

Humidity 73%
Wind Speed W 13 mph
Barometer 29.98 in (1015.3 mb)
Dewpoint 26°F (-3°C)
Visibility 10.00 mi
Wind Chill25°F (-4°C)
Last update 12 Mar 11:56 pm EDT
Extended Forecast for

Brentwood NY

  • Overnight

    Overnight: Mostly clear, with a low around 30. West wind around 9 mph.

    Low: 30 °F

    Mostly Clear

  • Friday

    Friday: Increasing clouds, with a high near 46. Light and variable wind becoming south 9 to 14 mph in the morning. Winds could gust as high as 24 mph.

    High: 46 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 37. South wind 11 to 14 mph, with gusts as high as 32 mph.

    Low: 37 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 50. West wind 15 to 17 mph, with gusts as high as 31 mph.

    High: 50 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 32. Northwest wind 5 to 8 mph becoming calm after midnight.

    Low: 32 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 48.

    High: 48 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Rain, mainly after 2am. Low around 40. Chance of precipitation is 80%.

    Low: 40 °F

    Chance Rain
    then Rain

  • Monday

    Monday: Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.

    High: 56 °F

    Rain and
    Breezy

  • Monday Night

    Monday Night: Rain, mainly before 2am. Low around 34. Chance of precipitation is 80%.

    Low: 34 °F

    Rain

Detailed Forecast

Overnight
Mostly clear, with a low around 30. West wind around 9 mph.
Friday
Increasing clouds, with a high near 46. Light and variable wind becoming south 9 to 14 mph in the morning. Winds could gust as high as 24 mph.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 37. South wind 11 to 14 mph, with gusts as high as 32 mph.
Saturday
Sunny, with a high near 50. West wind 15 to 17 mph, with gusts as high as 31 mph.
Saturday Night
Increasing clouds, with a low around 32. Northwest wind 5 to 8 mph becoming calm after midnight.
Sunday
Mostly cloudy, with a high near 48.
Sunday Night
Rain, mainly after 2am. Low around 40. Chance of precipitation is 80%.
Monday
Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.
Monday Night
Rain, mainly before 2am. Low around 34. Chance of precipitation is 80%.
Tuesday
A 30 percent chance of rain before 8am. Mostly sunny, with a high near 44.
Tuesday Night
Partly cloudy, with a low around 25.
Wednesday
Sunny, with a high near 38.
Wednesday Night
Partly cloudy, with a low around 28.
Thursday
Mostly sunny, with a high near 42.
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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:
6:03 pm EDT Mar 12, 2026
Forecast Valid:
12am EDT Mar 13, 2026-6pm EDT Mar 19, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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