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.

Partly Cloudy

81°F

27°C

Humidity 67%
Wind Speed NW 3 mph
Barometer 29.97 in (1014.7 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 9 Aug 8:56 pm EDT
Extended Forecast for

Ronkonkoma NY

Heat Advisory August 9, 09:32pm until August 10, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 9, 09:32pm until August 10, 07:00pm

    NOW until 7:00pm Mon

    Heat Advisory

  • Tonight

    Low: 71 °F

    Mostly Clear

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Sunny, with a high near 88. Light and variable wind becoming southwest 8 to 13 mph in the morning.

    High: 88 °F

    Sunny then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 30 percent chance of showers and thunderstorms before 11pm. Cloudy during the early evening, then gradual clearing, with a low around 74. West wind around 9 mph.

    Low: 74 °F

    Chance
    T-storms then
    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 88. West wind 9 to 11 mph.

    High: 88 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 69. Northwest wind 6 to 8 mph.

    Low: 69 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 71.

    Low: 71 °F

    Partly Cloudy
    then Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms before 8am, then a chance of showers between 8am and 2pm. Mostly sunny, with a high near 86. Chance of precipitation is 30%.

    High: 86 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 71. Light and variable wind becoming north around 5 mph.
Monday
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Sunny, with a high near 88. Light and variable wind becoming southwest 8 to 13 mph in the morning.
Monday Night
A 30 percent chance of showers and thunderstorms before 11pm. Cloudy during the early evening, then gradual clearing, with a low around 74. West wind around 9 mph.
Tuesday
Mostly sunny, with a high near 88. West wind 9 to 11 mph.
Tuesday Night
Partly cloudy, with a low around 69. Northwest wind 6 to 8 mph.
Wednesday
Mostly sunny, with a high near 84.
Wednesday Night
A 40 percent chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 71.
Thursday
A chance of showers and thunderstorms before 8am, then a chance of showers between 8am and 2pm. Mostly sunny, with a high near 86. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 66.
Friday
Sunny, with a high near 82.
Friday Night
Mostly clear, with a low around 64.
Saturday
Sunny, with a high near 81.
Saturday Night
Partly cloudy, with a low around 64.
Sunday
Mostly sunny, with a high near 80.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Ronkonkoma NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
2:26 pm EDT Aug 9, 2026
Forecast Valid:
9pm EDT Aug 9, 2026-6pm EDT Aug 16, 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