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.

Overcast

63°F

17°C

Humidity 93%
Wind Speed E 6 mph
Barometer 30.16 in (1021.2 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 16 Jun 8:56 am EDT
Extended Forecast for

Lake Ronkonkoma NY

  • Today

    Today: Mostly cloudy, with a high near 69. East wind 8 to 10 mph.

    High: 69 °F

    Mostly Cloudy

  • Tonight

    Tonight: A 20 percent chance of light rain after 2am. Mostly cloudy, with a low around 61. East wind 5 to 7 mph.

    Low: 61 °F

    Mostly Cloudy
    then Slight
    Chance Light
    Rain

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 72. East wind 6 to 8 mph.

    High: 72 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: A 50 percent chance of showers. Cloudy, with a low around 63. Southeast wind around 5 mph becoming calm in the evening.

    Low: 63 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 82. Southwest wind 3 to 8 mph. Chance of precipitation is 30%.

    High: 82 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 67.

    Low: 67 °F

    Partly Cloudy

  • Juneteenth

    Juneteenth: Sunny, with a high near 88.

    High: 88 °F

    Sunny

  • Thursday Night

    Thursday Night: A chance of showers between 8pm and 2am. Partly cloudy, with a low around 67. Chance of precipitation is 30%.

    Low: 67 °F

    Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 83.

    High: 83 °F

    Sunny

Detailed Forecast

Today
Mostly cloudy, with a high near 69. East wind 8 to 10 mph.
Tonight
A 20 percent chance of light rain after 2am. Mostly cloudy, with a low around 61. East wind 5 to 7 mph.
Tuesday
Mostly cloudy, with a high near 72. East wind 6 to 8 mph.
Tuesday Night
A 50 percent chance of showers. Cloudy, with a low around 63. Southeast wind around 5 mph becoming calm in the evening.
Wednesday
A chance of showers, with thunderstorms also possible after 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 82. Southwest wind 3 to 8 mph. Chance of precipitation is 30%.
Wednesday Night
Partly cloudy, with a low around 67.
Juneteenth
Sunny, with a high near 88.
Thursday Night
A chance of showers between 8pm and 2am. Partly cloudy, with a low around 67. Chance of precipitation is 30%.
Friday
Sunny, with a high near 83.
Friday Night
Partly cloudy, with a low around 63.
Saturday
Sunny, with a high near 81.
Saturday Night
Partly cloudy, with a low around 65.
Sunday
Mostly sunny, with a high near 84.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.11°W (Elev. 98 ft)
Last Update:
6:40 pm EDT Jun 15, 2025
Forecast Valid:
9am EDT Jun 16, 2025-6pm EDT Jun 22, 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