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

74°F

23°C

Humidity 91%
Wind Speed SW 9 mph
Barometer 29.89 in (1012.2 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Last update 18 Aug 8:56 pm EDT
Extended Forecast for

Lake Grove NY

  • Tonight

    Tonight: Increasing clouds, with a low around 68. Light southwest wind.

    Low: 68 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Mostly cloudy through mid morning, then gradual clearing, with a high near 85. Calm wind becoming west around 6 mph in the afternoon.

    High: 85 °F

    Becoming
    Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 70. Southwest wind 3 to 6 mph.

    Low: 70 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 83. West wind 3 to 5 mph.

    High: 83 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 64. Light and variable wind. Chance of precipitation is 30%.

    Low: 64 °F

    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

  • Friday Night

    Friday Night: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Mostly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: A 50 percent chance of showers. Partly sunny, with a high near 78.

    High: 78 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers

Detailed Forecast

Tonight
Increasing clouds, with a low around 68. Light southwest wind.
Wednesday
Mostly cloudy through mid morning, then gradual clearing, with a high near 85. Calm wind becoming west around 6 mph in the afternoon.
Wednesday Night
Partly cloudy, with a low around 70. Southwest wind 3 to 6 mph.
Thursday
A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 83. West wind 3 to 5 mph.
Thursday Night
A chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 64. Light and variable wind. Chance of precipitation is 30%.
Friday
Mostly sunny, with a high near 81.
Friday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 65.
Saturday
A 50 percent chance of showers. Partly sunny, with a high near 78.
Saturday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 65.
Sunday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Sunday Night
A 30 percent chance of showers. Partly cloudy, with a low around 64.
Monday
Sunny, with a high near 81.
Monday Night
Mostly clear, with a low around 64.
Tuesday
Sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lake Grove NY
 40.85°N 73.1°W (Elev. 144 ft)
Last Update:
2:34 pm EDT Aug 18, 2026
Forecast Valid:
9pm EDT Aug 18, 2026-6pm EDT Aug 25, 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