Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fog

65°F

18°C

Humidity 100%
Wind Speed S 3 mph
Barometer 29.96 in (1014.3 mb)
Dewpoint 65°F (18°C)
Visibility 0.25 mi
Last update 18 Jun 4:56 am EDT
Extended Forecast for

Lake Ronkonkoma NY

Dense Fog Advisory until June 18, 07:00am
Click here for hazard details and duration
Dense Fog Advisory
  •  
    Dense Fog Advisory until June 18, 07:00am

    NOW until 7:00am Wed

    Dense Fog Advisory

  • Overnight

    Low: 66 °F

    Chance
    Showers and
    Dense Fog

  • Wednesday

    Wednesday: A chance of showers before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers likely and possibly a thunderstorm after 5pm.  Widespread dense fog, mainly before 7am.  Otherwise, cloudy, with a high near 79. South wind 5 to 7 mph.  Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 79 °F

    Chance
    Showers and
    Dense Fog
    then Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm.  Mostly cloudy, with a low around 67. South wind around 5 mph becoming light and variable  in the evening.  Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 67 °F

    Showers
    Likely then
    Mostly Cloudy

  • Juneteenth

    Juneteenth: A 30 percent chance of showers and thunderstorms after 2pm. Some of the storms could be severe.  Increasing clouds, with a high near 87. Southwest wind 6 to 13 mph.

    High: 87 °F

    Partly Sunny
    then Severe
    Thunderstorms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Some of the storms could be severe.  Cloudy, then gradually becoming partly cloudy, with a low around 65. Southwest wind around 11 mph.  Chance of precipitation is 40%.

    Low: 65 °F

    Severe
    Thunderstorms
    then Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

Detailed Forecast

Overnight
A 50 percent chance of showers. Widespread dense fog. Otherwise, cloudy, with a low around 66. Light south wind.
Wednesday
A chance of showers before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers likely and possibly a thunderstorm after 5pm. Widespread dense fog, mainly before 7am. Otherwise, cloudy, with a high near 79. South wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm. Mostly cloudy, with a low around 67. South wind around 5 mph becoming light and variable in the evening. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Juneteenth
A 30 percent chance of showers and thunderstorms after 2pm. Some of the storms could be severe. Increasing clouds, with a high near 87. Southwest wind 6 to 13 mph.
Thursday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Some of the storms could be severe. Cloudy, then gradually becoming partly cloudy, with a low around 65. Southwest wind around 11 mph. Chance of precipitation is 40%.
Friday
Sunny, with a high near 84.
Friday Night
Mostly clear, with a low around 65.
Saturday
Sunny, with a high near 84.
Saturday Night
Mostly cloudy, with a low around 67.
Sunday
Partly sunny, with a high near 85.
Sunday Night
Partly cloudy, with a low around 70.
Monday
Sunny, with a high near 90.
Monday Night
Mostly clear, with a low around 70.
Tuesday
Sunny, with a high near 91.
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ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.14°W (Elev. 98 ft)
3:06 am EDT Jun 18, 2025
5am EDT Jun 18, 2025-6pm EDT Jun 24, 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