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 49%
Wind Speed SW 9 mph
Barometer 29.87 in (1011.5 mb)
Dewpoint 22°F (-6°C)
Visibility 10.00 mi
Wind Chill34°F (1°C)
Last update 12 Nov 4:56 am EST
Extended Forecast for

Lake Ronkonkoma NY

  • Today

    Today: Partly sunny, with a high near 51. Southwest wind 10 to 15 mph, with gusts as high as 29 mph.

    High: 51 °F

    Partly Sunny

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming mostly clear, with a low around 40. West wind around 11 mph, with gusts as high as 23 mph.

    Low: 40 °F

    Decreasing
    Clouds

  • Thursday

    Thursday: Mostly sunny, with a high near 52. West wind 10 to 14 mph, with gusts as high as 29 mph.

    High: 52 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 36. Northwest wind 8 to 10 mph, with gusts as high as 23 mph.

    Low: 36 °F

    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 49. West wind 8 to 14 mph.

    High: 49 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 33.

    Low: 33 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 50.

    High: 50 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 50 percent chance of rain. Mostly cloudy, with a low around 39.

    Low: 39 °F

    Chance Rain

  • Sunday

    Sunday: Rain likely, mainly before 1pm. Mostly cloudy, with a high near 60. Chance of precipitation is 70%.

    High: 60 °F

    Rain Likely

Detailed Forecast

Today
Partly sunny, with a high near 51. Southwest wind 10 to 15 mph, with gusts as high as 29 mph.
Tonight
Mostly cloudy, then gradually becoming mostly clear, with a low around 40. West wind around 11 mph, with gusts as high as 23 mph.
Thursday
Mostly sunny, with a high near 52. West wind 10 to 14 mph, with gusts as high as 29 mph.
Thursday Night
Mostly clear, with a low around 36. Northwest wind 8 to 10 mph, with gusts as high as 23 mph.
Friday
Mostly sunny, with a high near 49. West wind 8 to 14 mph.
Friday Night
Mostly clear, with a low around 33.
Saturday
Mostly sunny, with a high near 50.
Saturday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 39.
Sunday
Rain likely, mainly before 1pm. Mostly cloudy, with a high near 60. Chance of precipitation is 70%.
Sunday Night
Partly cloudy, with a low around 38.
Monday
Mostly sunny, with a high near 50.
Monday Night
Partly cloudy, with a low around 36.
Tuesday
Partly sunny, with a high near 49.
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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:
1:00 am EST Nov 12, 2025
Forecast Valid:
5am EST Nov 12, 2025-6pm EST Nov 18, 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