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.

Fair

59°F

15°C

Humidity 67%
Wind Speed SW 10 mph
Barometer 29.91 in (1012.9 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 7 Oct 6:56 pm EDT
Extended Forecast for

Lake Ronkonkoma NY

  • Tonight

    Tonight: Mostly clear, with a low around 59. Southwest wind around 10 mph.

    Low: 59 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 73. West wind 9 to 13 mph.

    High: 73 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 52. Northwest wind 3 to 6 mph.

    Low: 52 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 69. West wind 6 to 10 mph.

    High: 69 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 50. Northwest wind around 5 mph becoming calm in the evening.

    Low: 50 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 68.

    High: 68 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 57.

    Low: 57 °F

    Partly Cloudy

  • Sunday

    Sunday: Showers. High near 67. Chance of precipitation is 90%.

    High: 67 °F

    Showers

  • Sunday Night

    Sunday Night: Showers, with thunderstorms also possible after 2am. Low around 61. Chance of precipitation is 80%.

    Low: 61 °F

    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 59. Southwest wind around 10 mph.
Thursday
Sunny, with a high near 73. West wind 9 to 13 mph.
Thursday Night
Mostly clear, with a low around 52. Northwest wind 3 to 6 mph.
Friday
Sunny, with a high near 69. West wind 6 to 10 mph.
Friday Night
Mostly clear, with a low around 50. Northwest wind around 5 mph becoming calm in the evening.
Saturday
Sunny, with a high near 68.
Saturday Night
Partly cloudy, with a low around 57.
Sunday
Showers. High near 67. Chance of precipitation is 90%.
Sunday Night
Showers, with thunderstorms also possible after 2am. Low around 61. Chance of precipitation is 80%.
Columbus Day
Showers likely and possibly a thunderstorm before 8am, then a chance of showers between 8am and 2pm. Mostly cloudy, with a high near 71. Chance of precipitation is 60%.
Monday Night
Mostly cloudy, with a low around 57.
Tuesday
A 30 percent chance of showers. Partly sunny, with a high near 66.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 48.
Wednesday
Mostly sunny, with a high near 58.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.11°W (Elev. 98 ft)
Last Update:
2:28 pm EDT Oct 7, 2026
Forecast Valid:
7pm EDT Oct 7, 2026-6pm EDT Oct 14, 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