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

75°F

24°C

Humidity 39%
Wind Speed N 10 mph
Barometer 30.22 in (1023.2 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 29 Aug 1:56 pm EDT
Extended Forecast for

Lake Grove NY

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 77. Light northwest wind.

    High: 77 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 61. Light southwest wind.

    Low: 61 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 80. Light west wind becoming southwest 6 to 11 mph in the morning.

    High: 80 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A 50 percent chance of showers, mainly after 8pm. Partly cloudy during the early evening, then becoming cloudy, with a low around 67. West wind 5 to 9 mph.

    Low: 67 °F

    Chance
    Showers

  • Monday

    Monday: A 20 percent chance of showers. Partly sunny, with a high near 80. West wind 3 to 5 mph.

    High: 80 °F

    Slight Chance
    Showers

  • Monday Night

    Monday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A 50 percent chance of showers. Mostly cloudy, with a high near 77.

    High: 77 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A 30 percent chance of showers. Mostly cloudy, with a high near 79.

    High: 79 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 77. Light northwest wind.
Tonight
Mostly clear, with a low around 61. Light southwest wind.
Sunday
Mostly sunny, with a high near 80. Light west wind becoming southwest 6 to 11 mph in the morning.
Sunday Night
A 50 percent chance of showers, mainly after 8pm. Partly cloudy during the early evening, then becoming cloudy, with a low around 67. West wind 5 to 9 mph.
Monday
A 20 percent chance of showers. Partly sunny, with a high near 80. West wind 3 to 5 mph.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 65.
Tuesday
A 50 percent chance of showers. Mostly cloudy, with a high near 77.
Tuesday Night
Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.
Wednesday
A 30 percent chance of showers. Mostly cloudy, with a high near 79.
Wednesday Night
Showers likely, mainly before 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 60%.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Thursday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 64.
Friday
Mostly sunny, with a high near 77.
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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:
6:45 am EDT Aug 29, 2026
Forecast Valid:
2pm EDT Aug 29, 2026-6pm EDT Sep 4, 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