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.

A Few Clouds

63°F

17°C

Humidity 58%
Wind Speed S 7 mph
Barometer 29.97 in (1015.1 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 10 Mar 3:56 pm EDT
Extended Forecast for

Lake Ronkonkoma NY

  • Tonight

    Tonight: Patchy fog after 3am. Otherwise, partly cloudy, with a low around 39. South wind 5 to 8 mph becoming calm in the evening.

    Low: 39 °F

    Partly Cloudy
    then Patchy
    Fog

  • Wednesday

    Wednesday: A 30 percent chance of showers, mainly after 2pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 56. Light south wind increasing to 5 to 10 mph in the morning.

    High: 56 °F

    Chance
    Showers and
    Patchy Fog

  • Wednesday Night

    Wednesday Night: A chance of rain before 11pm, then a chance of rain and thunderstorms between 11pm and 2am, then a chance of rain after 2am. Mostly cloudy, with a low around 49. South wind around 10 mph, with gusts as high as 23 mph. Chance of precipitation is 40%.

    Low: 49 °F

    Chance Rain

  • Thursday

    Thursday: Rain likely before 5pm, then a chance of rain and snow. Cloudy, with a temperature falling to around 42 by 5pm. Northwest wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 70%. Little or no snow accumulation expected.

    High: 55 °F⇓

    Rain Likely
    then
    Rain/Snow
    Likely

  • Thursday Night

    Thursday Night: A chance of rain and snow before 8pm. Mostly cloudy, then gradually becoming clear, with a low around 30. Northwest wind 6 to 8 mph. Chance of precipitation is 30%.

    Low: 30 °F

    Chance
    Rain/Snow
    then Mostly
    Clear

  • Friday

    Friday: Partly sunny, with a high near 45.

    High: 45 °F

    Partly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 35.

    Low: 35 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 49.

    High: 49 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 33.

    Low: 33 °F

    Partly Cloudy

Detailed Forecast

Tonight
Patchy fog after 3am. Otherwise, partly cloudy, with a low around 39. South wind 5 to 8 mph becoming calm in the evening.
Wednesday
A 30 percent chance of showers, mainly after 2pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 56. Light south wind increasing to 5 to 10 mph in the morning.
Wednesday Night
A chance of rain before 11pm, then a chance of rain and thunderstorms between 11pm and 2am, then a chance of rain after 2am. Mostly cloudy, with a low around 49. South wind around 10 mph, with gusts as high as 23 mph. Chance of precipitation is 40%.
Thursday
Rain likely before 5pm, then a chance of rain and snow. Cloudy, with a temperature falling to around 42 by 5pm. Northwest wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 70%. Little or no snow accumulation expected.
Thursday Night
A chance of rain and snow before 8pm. Mostly cloudy, then gradually becoming clear, with a low around 30. Northwest wind 6 to 8 mph. Chance of precipitation is 30%.
Friday
Partly sunny, with a high near 45.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 35.
Saturday
Sunny, with a high near 49.
Saturday Night
Partly cloudy, with a low around 33.
Sunday
Mostly cloudy, with a high near 51.
Sunday Night
Rain. Low around 42. Chance of precipitation is 80%.
Monday
Rain. High near 53. Chance of precipitation is 80%.
Monday Night
Rain and snow likely. Mostly cloudy, with a low around 26. Chance of precipitation is 60%.
Tuesday
A 30 percent chance of snow. Mostly sunny, with a high near 37.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lake Ronkonkoma NY
 40.83°N 73.11°W (Elev. 98 ft)
Last Update:
1:57 pm EDT Mar 10, 2026
Forecast Valid:
4pm EDT Mar 10, 2026-6pm EDT Mar 17, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation