National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

51°F

11°C

Humidity 36%
Wind Speed N 17 G 26 mph
Barometer 30.12 in (1020.0 mb)
Dewpoint 25°F (-4°C)
Visibility 10.00 mi
Wind Chill45°F (7°C)
Last update 20 Apr 2:56 pm EDT
Extended Forecast for

Lake Ronkonkoma NY

Freeze Warning April 21, 12:00am until April 21, 09:00am
Click here for hazard details and duration
Freeze Warning

  • This Afternoon

    This Afternoon: Scattered showers, mainly before 4pm. Partly sunny, with a high near 53. Northwest wind around 14 mph. Chance of precipitation is 40%.

    High: 53 °F

    Scattered
    Showers

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming clear, with a low around 31. North wind 7 to 10 mph.

    Low: 31 °F

    Decreasing
    Clouds

  • Tuesday

    Tuesday: Sunny, with a high near 51. Wind chill values between 25 and 35 early. North wind 5 to 7 mph becoming south in the afternoon.

    High: 51 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers after 2am. Increasing clouds, with a low around 38. South wind around 7 mph.

    Low: 38 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Wednesday

    Wednesday: A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 55. South wind 8 to 10 mph.

    High: 55 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 43.

    Low: 43 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 64.

    High: 64 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 44.

    Low: 44 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 61.

    High: 61 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Scattered showers, mainly before 4pm. Partly sunny, with a high near 53. Northwest wind around 14 mph. Chance of precipitation is 40%.
Tonight
Mostly cloudy, then gradually becoming clear, with a low around 31. North wind 7 to 10 mph.
Tuesday
Sunny, with a high near 51. Wind chill values between 25 and 35 early. North wind 5 to 7 mph becoming south in the afternoon.
Tuesday Night
A 20 percent chance of showers after 2am. Increasing clouds, with a low around 38. South wind around 7 mph.
Wednesday
A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 55. South wind 8 to 10 mph.
Wednesday Night
Mostly cloudy, with a low around 43.
Thursday
Mostly sunny, with a high near 64.
Thursday Night
Mostly cloudy, with a low around 44.
Friday
Mostly sunny, with a high near 61.
Friday Night
Partly cloudy, with a low around 44.
Saturday
A 40 percent chance of showers. Mostly cloudy, with a high near 54.
Saturday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 44.
Sunday
A 30 percent chance of showers. Mostly cloudy, with a high near 58.
Sunday Night
Mostly cloudy, with a low around 43.
Monday
Partly sunny, with a high near 59.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.11°W (Elev. 98 ft)
Last Update:
3:44 pm EDT Apr 20, 2026
Forecast Valid:
3pm EDT Apr 20, 2026-6pm EDT Apr 27, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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