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.

Overcast and Breezy

49°F

9°C

Humidity 66%
Wind Speed SW 23 G 36 mph
Barometer 29.48 in (998.2 mb)
Dewpoint 38°F (3°C)
Visibility 10.00 mi
Wind Chill42°F (6°C)
Last update 10 Dec 2:56 pm EST
Extended Forecast for

Holtsville NY

  • This Afternoon

    This Afternoon: A 30 percent chance of rain. Cloudy, with a high near 48. Southwest wind around 16 mph, with gusts as high as 30 mph.

    High: 48 °F

    Chance Rain

  • Tonight

    Tonight: Rain, mainly before 10pm. Low around 28. Southwest wind 10 to 14 mph, with gusts as high as 28 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 28 °F

    Rain then
    Chance Rain

  • Thursday

    Thursday: A 20 percent chance of snow showers after 1pm. Mostly sunny, with a high near 36. Wind chill values between 15 and 25. West wind 16 to 18 mph, with gusts as high as 41 mph.

    High: 36 °F

    Mostly Sunny
    then Slight
    Chance Snow
    Showers

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 24. Wind chill values between 10 and 20. West wind 14 to 17 mph, with gusts as high as 41 mph.

    Low: 24 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 35. West wind 10 to 15 mph, with gusts as high as 28 mph.

    High: 35 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 23.

    Low: 23 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 39.

    High: 39 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A 40 percent chance of snow after 1am. Mostly cloudy, with a low around 25.

    Low: 25 °F

    Mostly Cloudy
    then Chance
    Snow

  • Sunday

    Sunday: A 40 percent chance of snow before 1pm. Mostly cloudy, with a high near 33.

    High: 33 °F

    Chance Snow

Detailed Forecast

This Afternoon
A 30 percent chance of rain. Cloudy, with a high near 48. Southwest wind around 16 mph, with gusts as high as 30 mph.
Tonight
Rain, mainly before 10pm. Low around 28. Southwest wind 10 to 14 mph, with gusts as high as 28 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Thursday
A 20 percent chance of snow showers after 1pm. Mostly sunny, with a high near 36. Wind chill values between 15 and 25. West wind 16 to 18 mph, with gusts as high as 41 mph.
Thursday Night
Partly cloudy, with a low around 24. Wind chill values between 10 and 20. West wind 14 to 17 mph, with gusts as high as 41 mph.
Friday
Mostly sunny, with a high near 35. West wind 10 to 15 mph, with gusts as high as 28 mph.
Friday Night
Partly cloudy, with a low around 23.
Saturday
Partly sunny, with a high near 39.
Saturday Night
A 40 percent chance of snow after 1am. Mostly cloudy, with a low around 25.
Sunday
A 40 percent chance of snow before 1pm. Mostly cloudy, with a high near 33.
Sunday Night
Partly cloudy, with a low around 19.
Monday
Sunny, with a high near 32.
Monday Night
Mostly cloudy, with a low around 21.
Tuesday
Mostly sunny, with a high near 35.
Tuesday Night
Partly cloudy, with a low around 25.
Wednesday
Partly sunny, with a high near 42.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Holtsville NY
 40.82°N 73.05°W (Elev. 112 ft)
Last Update:
3:34 pm EST Dec 10, 2025
Forecast Valid:
3pm EST Dec 10, 2025-6pm EST Dec 17, 2025
 
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