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.

Mostly Cloudy

60°F

16°C

Humidity 44%
Wind Speed NE 15 mph
Barometer 30.37 in (1028.5 mb)
Dewpoint 38°F (3°C)
Visibility 10.00 mi
Last update 22 May 9:56 am EDT
Extended Forecast for

Holtsville NY

  • Today

    Today: Partly sunny, with a high near 67. East wind around 15 mph.

    High: 67 °F

    Partly Sunny

  • Tonight

    Tonight: Cloudy, with a low around 48. East wind 6 to 9 mph.

    Low: 48 °F

    Cloudy

  • Saturday

    Saturday: A chance of showers before 2pm, then rain likely after 2pm. Cloudy, with a high near 59. East wind 9 to 16 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 59 °F

    Rain Likely

  • Saturday Night

    Saturday Night: Rain, with thunderstorms also possible after 2am. Steady temperature around 53. East wind 14 to 17 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.

    Low: 53 °F

    Rain

  • Sunday

    Sunday: Rain and possibly a thunderstorm before 2pm, then rain likely. High near 63. Breezy, with an east wind 15 to 20 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

    High: 63 °F

    Rain and
    Breezy

  • Sunday Night

    Sunday Night: Rain likely with patchy drizzle before 2am, then patchy drizzle with a chance of rain after 2am. Cloudy, with a low around 56. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 56 °F

    Rain Likely

  • Memorial Day

    Memorial Day: Showers likely, mainly before 2pm. Mostly cloudy, with a high near 76. Chance of precipitation is 60%.

    High: 76 °F

    Showers
    Likely

  • Monday Night

    Monday Night: A 30 percent chance of showers before 2am. Mostly cloudy, with a low around 59.

    Low: 59 °F

    Chance
    Showers

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 78.

    High: 78 °F

    Mostly Cloudy

Detailed Forecast

Today
Partly sunny, with a high near 67. East wind around 15 mph.
Tonight
Cloudy, with a low around 48. East wind 6 to 9 mph.
Saturday
A chance of showers before 2pm, then rain likely after 2pm. Cloudy, with a high near 59. East wind 9 to 16 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday Night
Rain, with thunderstorms also possible after 2am. Steady temperature around 53. East wind 14 to 17 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.
Sunday
Rain and possibly a thunderstorm before 2pm, then rain likely. High near 63. Breezy, with an east wind 15 to 20 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Sunday Night
Rain likely with patchy drizzle before 2am, then patchy drizzle with a chance of rain after 2am. Cloudy, with a low around 56. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Memorial Day
Showers likely, mainly before 2pm. Mostly cloudy, with a high near 76. Chance of precipitation is 60%.
Monday Night
A 30 percent chance of showers before 2am. Mostly cloudy, with a low around 59.
Tuesday
Mostly cloudy, with a high near 78.
Tuesday Night
Mostly cloudy, with a low around 60.
Wednesday
Partly sunny, with a high near 80.
Wednesday Night
Partly cloudy, with a low around 61.
Thursday
Mostly sunny, with a high near 77.
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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:
6:21 am EDT May 22, 2026
Forecast Valid:
10am EDT May 22, 2026-6pm EDT May 28, 2026
 
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