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.

Partly Cloudy and Breezy

N/A

Humidity NA
Wind Speed NW 21 G 35 mph
Barometer 29.96 in
Dewpoint N/A
Visibility 10.00 mi
Last update 12 Jan 12:56 am EST
Extended Forecast for

Lake Ronkonkoma NY

  • Overnight

    Overnight: Mostly clear, with a steady temperature around 31. Wind chill values between 20 and 25. West wind around 13 mph, with gusts as high as 34 mph.

    Low: 31 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 41. Wind chill values between 20 and 30. Southwest wind 10 to 13 mph, with gusts as high as 25 mph.

    High: 41 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 30. West wind around 7 mph.

    Low: 30 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 44. West wind 5 to 9 mph.

    High: 44 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a steady temperature around 39. South wind around 7 mph, with gusts as high as 20 mph.

    Low: 39 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, with a high near 47.

    High: 47 °F

    Mostly Cloudy

  • Wednesday Night

    Wednesday Night: A 40 percent chance of rain after 1am. Cloudy, with a low around 34.

    Low: 34 °F

    Cloudy then
    Chance Rain

  • Thursday

    Thursday: A 40 percent chance of rain. Mostly cloudy, with a high near 42.

    High: 42 °F

    Chance Rain

  • Thursday Night

    Thursday Night: A chance of rain and snow before 1am, then a chance of snow. Mostly cloudy, with a low around 21. Chance of precipitation is 40%.

    Low: 21 °F

    Chance
    Rain/Snow

Detailed Forecast

Overnight
Mostly clear, with a steady temperature around 31. Wind chill values between 20 and 25. West wind around 13 mph, with gusts as high as 34 mph.
Monday
Mostly sunny, with a high near 41. Wind chill values between 20 and 30. Southwest wind 10 to 13 mph, with gusts as high as 25 mph.
Monday Night
Partly cloudy, with a low around 30. West wind around 7 mph.
Tuesday
Sunny, with a high near 44. West wind 5 to 9 mph.
Tuesday Night
Mostly cloudy, with a steady temperature around 39. South wind around 7 mph, with gusts as high as 20 mph.
Wednesday
Mostly cloudy, with a high near 47.
Wednesday Night
A 40 percent chance of rain after 1am. Cloudy, with a low around 34.
Thursday
A 40 percent chance of rain. Mostly cloudy, with a high near 42.
Thursday Night
A chance of rain and snow before 1am, then a chance of snow. Mostly cloudy, with a low around 21. Chance of precipitation is 40%.
Friday
Mostly sunny, with a high near 34.
Friday Night
Partly cloudy, with a low around 24.
Saturday
Mostly sunny, with a high near 38.
Saturday Night
Mostly cloudy, with a low around 26.
Sunday
A chance of rain and snow. Partly sunny, with a high near 36. Chance of precipitation is 40%.
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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:
1:42 pm EST Jan 11, 2026
Forecast Valid:
1am EST Jan 12, 2026-6pm EST Jan 18, 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