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

62°F

17°C

Humidity 28%
Wind Speed Vrbl 5 mph
Barometer 30.12 in (1020.0 mb)
Dewpoint 28°F (-2°C)
Visibility 10.00 mi
Last update 12 May 1:56 pm EDT
Extended Forecast for

Head of the Harbor NY

  • This Afternoon

    This Afternoon: Sunny, with a high near 68. West wind around 10 mph, with gusts as high as 20 mph.

    High: 68 °F

    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 52. South wind 7 to 10 mph, with gusts as high as 20 mph.

    Low: 52 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Mostly cloudy, with a high near 68. South wind 10 to 18 mph, with gusts as high as 30 mph.

    High: 68 °F

    Mostly Cloudy

  • Wednesday Night

    Wednesday Night: Showers, mainly after 2am. Low around 55. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 55 °F

    Chance
    Showers then
    Showers

  • Thursday

    Thursday: Showers, with thunderstorms also possible after 2pm. High near 68. Southeast wind around 9 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 68 °F

    Showers

  • Thursday Night

    Thursday Night: Showers likely, mainly before 2am. Mostly cloudy, with a low around 53. Chance of precipitation is 60%.

    Low: 53 °F

    Showers
    Likely

  • Friday

    Friday: A 40 percent chance of showers before 2pm. Partly sunny, with a high near 70.

    High: 70 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Partly cloudy, with a low around 55.

    Low: 55 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 68. West wind around 10 mph, with gusts as high as 20 mph.
Tonight
Increasing clouds, with a low around 52. South wind 7 to 10 mph, with gusts as high as 20 mph.
Wednesday
Mostly cloudy, with a high near 68. South wind 10 to 18 mph, with gusts as high as 30 mph.
Wednesday Night
Showers, mainly after 2am. Low around 55. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday
Showers, with thunderstorms also possible after 2pm. High near 68. Southeast wind around 9 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Thursday Night
Showers likely, mainly before 2am. Mostly cloudy, with a low around 53. Chance of precipitation is 60%.
Friday
A 40 percent chance of showers before 2pm. Partly sunny, with a high near 70.
Friday Night
Partly cloudy, with a low around 55.
Saturday
Sunny, with a high near 79.
Saturday Night
Mostly clear, with a low around 60.
Sunday
Sunny, with a high near 84.
Sunday Night
Partly cloudy, with a low around 59.
Monday
Mostly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Head of the Harbor NY
 40.9°N 73.15°W (Elev. 157 ft)
Last Update:
9:26 am EDT May 12, 2026
Forecast Valid:
2pm EDT May 12, 2026-6pm EDT May 18, 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