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

47°F

8°C

Humidity 86%
Wind Speed W 3 mph
Barometer 29.95 in (1014.1 mb)
Dewpoint 43°F (6°C)
Visibility 9.00 mi
Last update 21 Nov 10:56 pm EST
Extended Forecast for

Head of the Harbor NY

  • Tonight

    Tonight: Showers likely, mainly after 4am. Mostly cloudy, with a low around 42. Light west wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 42 °F

    Showers
    Likely

  • Saturday

    Saturday: Showers likely before 10am, then a chance of rain between 10am and 1pm. Cloudy through mid morning, then gradual clearing, with a high near 50. North wind 3 to 8 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

    High: 50 °F

    Showers
    Likely then
    Chance Rain

  • Saturday Night

    Saturday Night: Widespread frost, mainly after 5am. Otherwise, mostly clear, with a low around 33. North wind 3 to 7 mph.

    Low: 33 °F

    Mostly Clear
    then Frost

  • Sunday

    Sunday: Widespread frost, mainly before 8am. Otherwise, mostly sunny, with a high near 49. Light and variable wind becoming southwest 5 to 9 mph in the morning.

    High: 49 °F

    Frost then
    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 39. West wind around 8 mph.

    Low: 39 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 51.

    High: 51 °F

    Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 38.

    Low: 38 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 30 percent chance of rain after 1pm. Cloudy, with a high near 54.

    High: 54 °F

    Mostly Cloudy
    then Chance
    Rain

  • Tuesday Night

    Tuesday Night: Rain likely. Cloudy, with a low around 47. Chance of precipitation is 70%.

    Low: 47 °F

    Rain Likely

Detailed Forecast

Tonight
Showers likely, mainly after 4am. Mostly cloudy, with a low around 42. Light west wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Saturday
Showers likely before 10am, then a chance of rain between 10am and 1pm. Cloudy through mid morning, then gradual clearing, with a high near 50. North wind 3 to 8 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Saturday Night
Widespread frost, mainly after 5am. Otherwise, mostly clear, with a low around 33. North wind 3 to 7 mph.
Sunday
Widespread frost, mainly before 8am. Otherwise, mostly sunny, with a high near 49. Light and variable wind becoming southwest 5 to 9 mph in the morning.
Sunday Night
Partly cloudy, with a low around 39. West wind around 8 mph.
Monday
Sunny, with a high near 51.
Monday Night
Mostly cloudy, with a low around 38.
Tuesday
A 30 percent chance of rain after 1pm. Cloudy, with a high near 54.
Tuesday Night
Rain likely. Cloudy, with a low around 47. Chance of precipitation is 70%.
Wednesday
A 40 percent chance of rain. Mostly cloudy, with a high near 58.
Wednesday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 41.
Thanksgiving Day
Mostly sunny, with a high near 50.
Thursday Night
Partly cloudy, with a low around 34.
Friday
Mostly sunny, with a high near 44.
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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:
3:11 pm EST Nov 21, 2025
Forecast Valid:
11pm EST Nov 21, 2025-6pm EST Nov 28, 2025
 
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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