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.

Fair

76°F

24°C

Humidity 82%
Wind Speed SW 6 mph
Barometer 29.96 in (1014.3 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 9 Aug 1:56 am EDT
Extended Forecast for

Ronkonkoma NY

  • Overnight

    Overnight: Mostly clear, with a steady temperature around 77. West wind around 7 mph.

    Low: 77 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 90. West wind 7 to 10 mph.

    High: 90 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 71. Southwest wind 5 to 7 mph becoming light and variable after midnight.

    Low: 71 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 87. Light and variable wind becoming south 8 to 13 mph in the morning.

    High: 87 °F

    Sunny

  • Monday Night

    Monday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Partly cloudy, with a low around 74. West wind 7 to 9 mph. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87.

    High: 87 °F

    Sunny then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 70.

    Low: 70 °F

    Chance
    T-storms then
    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 70.

    Low: 70 °F

    Chance
    Showers

Detailed Forecast

Overnight
Mostly clear, with a steady temperature around 77. West wind around 7 mph.
Sunday
Sunny, with a high near 90. West wind 7 to 10 mph.
Sunday Night
Mostly clear, with a low around 71. Southwest wind 5 to 7 mph becoming light and variable after midnight.
Monday
Sunny, with a high near 87. Light and variable wind becoming south 8 to 13 mph in the morning.
Monday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Partly cloudy, with a low around 74. West wind 7 to 9 mph. Chance of precipitation is 30%.
Tuesday
A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87.
Tuesday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 70.
Wednesday
Mostly sunny, with a high near 85.
Wednesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 70.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 84.
Thursday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 68.
Friday
Mostly sunny, with a high near 82.
Friday Night
Partly cloudy, with a low around 64.
Saturday
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:
8:54 pm EDT Aug 8, 2026
Forecast Valid:
2am EDT Aug 9, 2026-6pm EDT Aug 15, 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