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.

Fog/Mist

67°F

19°C

Humidity 93%
Wind Speed N 13 G 24 mph
Barometer 30.03 in (1016.9 mb)
Dewpoint 65°F (18°C)
Visibility 6.00 mi
Last update 21 Aug 9:56 am EDT
Extended Forecast for

Ronkonkoma NY

  • Today

    Today: A 20 percent chance of showers. Partly sunny, with a high near 80. Northeast wind 13 to 16 mph.

    High: 80 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: Partly cloudy, with a low around 65. Northeast wind 5 to 8 mph.

    Low: 65 °F

    Partly Cloudy

  • Saturday

    Saturday: A 30 percent chance of showers after 2pm. Mostly cloudy, with a high near 75. Northeast wind 6 to 8 mph.

    High: 75 °F

    Mostly Cloudy
    then Chance
    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 8pm. Cloudy, with a low around 65. East wind around 7 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 65 °F

    Showers
    Likely

  • Sunday

    Sunday: A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 80. Southeast wind 7 to 11 mph becoming southwest in the morning. Chance of precipitation is 40%.

    High: 80 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 65.

    Low: 65 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 80.

    High: 80 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 62.

    Low: 62 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

Detailed Forecast

Today
A 20 percent chance of showers. Partly sunny, with a high near 80. Northeast wind 13 to 16 mph.
Tonight
Partly cloudy, with a low around 65. Northeast wind 5 to 8 mph.
Saturday
A 30 percent chance of showers after 2pm. Mostly cloudy, with a high near 75. Northeast wind 6 to 8 mph.
Saturday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 8pm. Cloudy, with a low around 65. East wind around 7 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Sunday
A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 80. Southeast wind 7 to 11 mph becoming southwest in the morning. Chance of precipitation is 40%.
Sunday Night
Partly cloudy, with a low around 65.
Monday
Sunny, with a high near 80.
Monday Night
Mostly clear, with a low around 62.
Tuesday
Sunny, with a high near 79.
Tuesday Night
Mostly clear, with a low around 63.
Wednesday
Sunny, with a high near 80.
Wednesday Night
A 40 percent chance of showers. Partly cloudy, with a low around 67.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 80.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Ronkonkoma NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
3:45 am EDT Aug 21, 2026
Forecast Valid:
10am EDT Aug 21, 2026-6pm EDT Aug 27, 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