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.

A Few Clouds

79°F

26°C

Humidity 88%
Wind Speed SW 12 mph
Barometer 30.08 in (1018.3 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 6 Aug 7:56 pm EDT
Extended Forecast for

Ronkonkoma NY

Heat Advisory August 6, 08:09pm until August 8, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 6, 08:09pm until August 8, 08:00pm

    NOW until 8:00pm Sat

    Heat Advisory

  • Tonight

    Low: 76 °F

    Partly Cloudy

  • Friday

    Friday: A slight chance of showers and thunderstorms between 2pm and 5pm. Mostly sunny, with a high near 87. Heat index values as high as 99. Light west wind becoming southwest 5 to 9 mph in the morning. Chance of precipitation is 20%.

    High: 87 °F

    Sunny then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A chance of showers and thunderstorms between 8pm and 2am. Mostly cloudy, with a low around 75. Southwest wind 5 to 7 mph becoming calm after midnight. Chance of precipitation is 50%.

    Low: 75 °F

    Chance
    T-storms

  • Saturday

    Saturday: A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Heat index values as high as 95. Southwest wind 8 to 13 mph.

    High: 88 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 74. Southwest wind 6 to 9 mph.

    Low: 74 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: Sunny, with a high near 88.

    High: 88 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 70.

    Low: 70 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

Detailed Forecast

Tonight
Partly cloudy, with a low around 76. Southwest wind 5 to 10 mph becoming light after midnight.
Friday
A slight chance of showers and thunderstorms between 2pm and 5pm. Mostly sunny, with a high near 87. Heat index values as high as 99. Light west wind becoming southwest 5 to 9 mph in the morning. Chance of precipitation is 20%.
Friday Night
A chance of showers and thunderstorms between 8pm and 2am. Mostly cloudy, with a low around 75. Southwest wind 5 to 7 mph becoming calm after midnight. Chance of precipitation is 50%.
Saturday
A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Heat index values as high as 95. Southwest wind 8 to 13 mph.
Saturday Night
A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 74. Southwest wind 6 to 9 mph.
Sunday
Sunny, with a high near 88.
Sunday Night
Mostly clear, with a low around 70.
Monday
Sunny, with a high near 87.
Monday Night
Partly cloudy, with a low around 73.
Tuesday
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 88.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 72.
Wednesday
Mostly sunny, with a high near 86.
Wednesday Night
A 30 percent chance of showers. Partly cloudy, with a low around 69.
Thursday
A 30 percent chance of showers. Mostly sunny, with a high near 84.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Ronkonkoma NY
 40.81°N 73.14°W (Elev. 49 ft)
Last Update:
8:05 pm EDT Aug 6, 2026
Forecast Valid:
8pm EDT Aug 6, 2026-6pm EDT Aug 13, 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