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

45°F

7°C

Humidity 49%
Wind Speed NW 17 G 30 mph
Barometer 30.00 in (1016.0 mb)
Dewpoint 27°F (-3°C)
Visibility 10.00 mi
Wind Chill38°F (3°C)
Last update 24 Dec 8:56 am EST
Extended Forecast for

Ronkonkoma NY

  • Today

    Today: Sunny, with a temperature falling to around 39 by 5pm. Breezy, with a northwest wind 15 to 21 mph, with gusts as high as 37 mph.

    High: 47 °F⇓

    Sunny and
    Breezy

  • Tonight

    Tonight: Partly cloudy, with a low around 29. North wind 5 to 9 mph becoming calm in the evening.

    Low: 29 °F

    Partly Cloudy

  • Christmas Day

    Christmas Day: A slight chance of rain and snow before 1pm. Mostly cloudy, with a high near 46. Southwest wind 6 to 15 mph becoming northwest in the afternoon. Chance of precipitation is 20%.

    High: 46 °F

    Slight Chance
    Rain/Snow

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 20. Wind chill values between 10 and 15. North wind 11 to 14 mph.

    Low: 20 °F

    Partly Cloudy

  • Friday

    Friday: A 30 percent chance of snow after 1pm. Mostly cloudy, with a high near 31. North wind 8 to 11 mph.

    High: 31 °F

    Partly Sunny
    then Chance
    Snow

  • Friday Night

    Friday Night: Snow. Low around 23. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible.

    Low: 23 °F

    Snow

  • Saturday

    Saturday: Snow likely before 1pm. Cloudy, with a high near 37. Chance of precipitation is 60%.

    High: 37 °F

    Snow Likely

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 28.

    Low: 28 °F

    Mostly Cloudy

  • Sunday

    Sunday: Rain likely, mainly after 1pm. Cloudy, with a high near 44. Chance of precipitation is 60%.

    High: 44 °F

    Chance Rain
    then Rain
    Likely

Detailed Forecast

Today
Sunny, with a temperature falling to around 39 by 5pm. Breezy, with a northwest wind 15 to 21 mph, with gusts as high as 37 mph.
Tonight
Partly cloudy, with a low around 29. North wind 5 to 9 mph becoming calm in the evening.
Christmas Day
A slight chance of rain and snow before 1pm. Mostly cloudy, with a high near 46. Southwest wind 6 to 15 mph becoming northwest in the afternoon. Chance of precipitation is 20%.
Thursday Night
Partly cloudy, with a low around 20. Wind chill values between 10 and 15. North wind 11 to 14 mph.
Friday
A 30 percent chance of snow after 1pm. Mostly cloudy, with a high near 31. North wind 8 to 11 mph.
Friday Night
Snow. Low around 23. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible.
Saturday
Snow likely before 1pm. Cloudy, with a high near 37. Chance of precipitation is 60%.
Saturday Night
Mostly cloudy, with a low around 28.
Sunday
Rain likely, mainly after 1pm. Cloudy, with a high near 44. Chance of precipitation is 60%.
Sunday Night
Rain. Low around 30. Chance of precipitation is 80%.
Monday
A 40 percent chance of rain. Partly sunny, with a high near 40. Breezy.
Monday Night
Partly cloudy, with a low around 21.
Tuesday
Partly sunny, with a high near 33.
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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:
9:17 am EST Dec 24, 2025
Forecast Valid:
9am EST Dec 24, 2025-6pm EST Dec 30, 2025
 
Forecast Discussion
 
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Additional Resources

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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