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

66°F

19°C

Humidity 49%
Wind Speed Vrbl 5 mph
Barometer 29.70 in (1005.5 mb)
Dewpoint 46°F (8°C)
Visibility 10.00 mi
Last update 14 May 3:56 pm EDT
Extended Forecast for

Lake Ronkonkoma NY

  • This Afternoon

    This Afternoon: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 66. West wind around 5 mph.

    High: 66 °F

    Chance
    Showers

  • Tonight

    Tonight: A chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 11pm. Partly cloudy, with a low around 51. Light northwest wind. Chance of precipitation is 30%.

    Low: 51 °F

    Chance
    Showers then
    Partly Cloudy

  • Friday

    Friday: A 20 percent chance of showers before 2pm. Mostly sunny, with a high near 68. North wind around 8 mph.

    High: 68 °F

    Slight Chance
    Showers

  • Friday Night

    Friday Night: Partly cloudy, with a low around 53. Calm wind.

    Low: 53 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 77. Light southwest wind increasing to 8 to 13 mph in the morning.

    High: 77 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 60.

    Low: 60 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 60.

    Low: 60 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 75.

    High: 75 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 66. West wind around 5 mph.
Tonight
A chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 11pm. Partly cloudy, with a low around 51. Light northwest wind. Chance of precipitation is 30%.
Friday
A 20 percent chance of showers before 2pm. Mostly sunny, with a high near 68. North wind around 8 mph.
Friday Night
Partly cloudy, with a low around 53. Calm wind.
Saturday
Sunny, with a high near 77. Light southwest wind increasing to 8 to 13 mph in the morning.
Saturday Night
Partly cloudy, with a low around 60.
Sunday
Mostly sunny, with a high near 84.
Sunday Night
Partly cloudy, with a low around 60.
Monday
Mostly sunny, with a high near 75.
Monday Night
Mostly clear, with a low around 58.
Tuesday
Sunny, with a high near 81.
Tuesday Night
Mostly clear, with a low around 64.
Wednesday
Mostly sunny, with a high near 83.
Wednesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 62.
Thursday
A chance of showers. Partly sunny, with a high near 78.
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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:
2:22 pm EDT May 14, 2026
Forecast Valid:
4pm EDT May 14, 2026-6pm EDT May 21, 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