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

40°F

4°C

Humidity 83%
Wind Speed Calm
Barometer 30.24 in (1024.1 mb)
Dewpoint 35°F (2°C)
Visibility 10.00 mi
Last update 4 Mar 5:56 pm EST
Extended Forecast for

Lake Grove NY

  • Tonight

    Tonight: A 30 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, increasing clouds, with a low around 31. Calm wind.

    Low: 31 °F

    Patchy Fog
    then Chance
    Rain and
    Patchy Fog

  • Thursday

    Thursday: Rain, mainly after 7am. Areas of fog before 1pm. High near 40. Calm wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 40 °F

    Rain and
    Areas Fog

  • Thursday Night

    Thursday Night: Rain. Steady temperature around 37. Northeast wind 7 to 9 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 37 °F

    Rain

  • Friday

    Friday: A 30 percent chance of rain before 1pm. Cloudy, with a high near 41. Northeast wind 6 to 9 mph.

    High: 41 °F

    Chance Rain

  • Friday Night

    Friday Night: A 20 percent chance of showers after 1am. Cloudy, with a low around 33. Light northeast wind.

    Low: 33 °F

    Cloudy then
    Slight Chance
    Showers

  • Saturday

    Saturday: Cloudy, with a high near 50.

    High: 50 °F

    Cloudy

  • Saturday Night

    Saturday Night: Showers likely, mainly before 1am. Cloudy, with a low around 40. Chance of precipitation is 60%.

    Low: 40 °F

    Showers
    Likely

  • Sunday

    Sunday: Partly sunny, with a high near 54.

    High: 54 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 39.

    Low: 39 °F

    Partly Cloudy

Detailed Forecast

Tonight
A 30 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, increasing clouds, with a low around 31. Calm wind.
Thursday
Rain, mainly after 7am. Areas of fog before 1pm. High near 40. Calm wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Rain. Steady temperature around 37. Northeast wind 7 to 9 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
A 30 percent chance of rain before 1pm. Cloudy, with a high near 41. Northeast wind 6 to 9 mph.
Friday Night
A 20 percent chance of showers after 1am. Cloudy, with a low around 33. Light northeast wind.
Saturday
Cloudy, with a high near 50.
Saturday Night
Showers likely, mainly before 1am. Cloudy, with a low around 40. Chance of precipitation is 60%.
Sunday
Partly sunny, with a high near 54.
Sunday Night
Partly cloudy, with a low around 39.
Monday
Mostly sunny, with a high near 52.
Monday Night
Partly cloudy, with a low around 40.
Tuesday
Partly sunny, with a high near 56.
Tuesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 43.
Wednesday
A 30 percent chance of rain. Mostly cloudy, with a high near 56.
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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:
4:45 pm EST Mar 4, 2026
Forecast Valid:
6pm EST Mar 4, 2026-6pm EDT Mar 11, 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