Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Light Rain

75°F

24°C

Humidity 90%
Wind Speed N 7 mph
Barometer 30.08 in (1018.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 14 Jul 9:56 pm EDT
Extended Forecast for

Lake Ronkonkoma NY

Flood Advisory until July 14, 11:00pm
Click here for hazard details and duration
...
  •  
    Flood Advisory until July 14, 11:00pm

    NOW until 11:00pm Mon

    Flood Advisory

  • Tonight

    Low: 73 °F

    Showers
    Likely and
    Patchy Fog

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm before 8am, then a chance of showers and thunderstorms, mainly between 8am and 11am.  Patchy fog before 10am.  Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon.  Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 83 °F

    Showers
    Likely and
    Patchy Fog
    then Slight
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Patchy fog after midnight.  Otherwise, partly cloudy, with a low around 72. Southwest wind 3 to 6 mph.

    Low: 72 °F

    Partly Cloudy
    then Patchy
    Fog

  • Wednesday

    Wednesday: A slight chance of showers, with thunderstorms also possible after 2pm.  Patchy fog before 11am.  Otherwise, partly sunny, with a high near 88. Heat index values as high as 95. Calm wind becoming south 5 to 9 mph in the morning.  Chance of precipitation is 20%.

    High: 88 °F

    Slight Chance
    T-storms and
    Patchy Fog

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 74. Southwest wind 6 to 8 mph.

    Low: 74 °F

    Chance
    T-storms

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 2pm.  Partly sunny, with a high near 90. Chance of precipitation is 30%.

    High: 90 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of thunderstorms before 8pm.  Partly cloudy, with a low around 76. Chance of precipitation is 30%.

    Low: 76 °F

    Chance
    T-storms then
    Partly Cloudy

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms after 2pm.  Mostly sunny, with a high near 91.

    High: 91 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Tonight
Showers likely and possibly a thunderstorm before 11pm, then a chance of showers and thunderstorms between 11pm and 2am, then showers likely and possibly a thunderstorm after 2am. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 73. South wind 3 to 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tuesday
Showers likely and possibly a thunderstorm before 8am, then a chance of showers and thunderstorms, mainly between 8am and 11am. Patchy fog before 10am. Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
Patchy fog after midnight. Otherwise, partly cloudy, with a low around 72. Southwest wind 3 to 6 mph.
Wednesday
A slight chance of showers, with thunderstorms also possible after 2pm. Patchy fog before 11am. Otherwise, partly sunny, with a high near 88. Heat index values as high as 95. Calm wind becoming south 5 to 9 mph in the morning. Chance of precipitation is 20%.
Wednesday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 74. Southwest wind 6 to 8 mph.
Thursday
A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 90. Chance of precipitation is 30%.
Thursday Night
A chance of thunderstorms before 8pm. Partly cloudy, with a low around 76. Chance of precipitation is 30%.
Friday
A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 91.
Friday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 71.
Saturday
Mostly sunny, with a high near 86.
Saturday Night
Partly cloudy, with a low around 71.
Sunday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 84.
Sunday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71.
Monday
Mostly sunny, with a high near 86.
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ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.11°W (Elev. 98 ft)
2:29 pm EDT Jul 14, 2025
10pm EDT Jul 14, 2025-6pm EDT Jul 21, 2025
 
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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