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

59°F

15°C

Humidity 38%
Wind Speed NW 5 mph
Barometer 29.92 in (1013.3 mb)
Dewpoint 33°F (1°C)
Visibility 10.00 mi
Last update 17 Oct 6:56 pm EDT
Extended Forecast for

Head of the Harbor NY

  • Tonight

    Tonight: Mostly clear, with a low around 42. North wind 6 to 9 mph.

    Low: 42 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 63. North wind around 5 mph becoming calm in the afternoon.

    High: 63 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 51. South wind 3 to 5 mph.

    Low: 51 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 70. South wind 6 to 15 mph.

    High: 70 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Showers, with thunderstorms also possible after 5am. Low around 56. South wind 14 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 56 °F

    Chance
    Showers then
    Showers

  • Monday

    Monday: Showers, mainly before 8am. High near 66. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    High: 66 °F

    Showers then
    Chance
    Showers

  • Monday Night

    Monday Night: Partly cloudy, with a low around 50.

    Low: 50 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 52.

    Low: 52 °F

    Chance
    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 42. North wind 6 to 9 mph.
Saturday
Sunny, with a high near 63. North wind around 5 mph becoming calm in the afternoon.
Saturday Night
Partly cloudy, with a low around 51. South wind 3 to 5 mph.
Sunday
Mostly sunny, with a high near 70. South wind 6 to 15 mph.
Sunday Night
Showers, with thunderstorms also possible after 5am. Low around 56. South wind 14 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday
Showers, mainly before 8am. High near 66. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Monday Night
Partly cloudy, with a low around 50.
Tuesday
Sunny, with a high near 67.
Tuesday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 52.
Wednesday
A 30 percent chance of showers before 2pm. Mostly sunny, with a high near 63.
Wednesday Night
Mostly clear, with a low around 48.
Thursday
Mostly sunny, with a high near 62.
Thursday Night
Partly cloudy, with a low around 48.
Friday
A 30 percent chance of showers. Partly sunny, with a high near 62.
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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:
4:43 pm EDT Oct 17, 2025
Forecast Valid:
7pm EDT Oct 17, 2025-6pm EDT Oct 24, 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