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.

Fair

N/A

Humidity NA
Wind Speed W 14 mph
Barometer 30.04 in
Dewpoint N/A
Visibility 10.00 mi
Last update 12 Jan 3:56 am EST
Extended Forecast for

Head of the Harbor NY

  • Today

    Today: Mostly sunny, with a high near 40. Wind chill values between 20 and 30. Southwest wind 13 to 15 mph, with gusts as high as 30 mph.

    High: 40 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 30. Southwest wind 7 to 9 mph.

    Low: 30 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 43. Southwest wind 6 to 9 mph.

    High: 43 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 37. South wind around 9 mph.

    Low: 37 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 46. Southwest wind 6 to 8 mph.

    High: 46 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers. Cloudy, with a low around 34.

    Low: 34 °F

    Chance
    Showers

  • Thursday

    Thursday: A chance of rain before 1pm, then a chance of rain and snow. Mostly cloudy, with a high near 43. Chance of precipitation is 40%.

    High: 43 °F

    Chance Rain
    then Chance
    Rain/Snow

  • Thursday Night

    Thursday Night: A 50 percent chance of snow. Mostly cloudy, with a low around 22.

    Low: 22 °F

    Chance Snow

  • Friday

    Friday: A 30 percent chance of snow before 1pm. Partly sunny, with a high near 33.

    High: 33 °F

    Chance Snow

Detailed Forecast

Today
Mostly sunny, with a high near 40. Wind chill values between 20 and 30. Southwest wind 13 to 15 mph, with gusts as high as 30 mph.
Tonight
Mostly clear, with a low around 30. Southwest wind 7 to 9 mph.
Tuesday
Mostly sunny, with a high near 43. Southwest wind 6 to 9 mph.
Tuesday Night
Mostly cloudy, with a low around 37. South wind around 9 mph.
Wednesday
A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 46. Southwest wind 6 to 8 mph.
Wednesday Night
A 40 percent chance of showers. Cloudy, with a low around 34.
Thursday
A chance of rain before 1pm, then a chance of rain and snow. Mostly cloudy, with a high near 43. Chance of precipitation is 40%.
Thursday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 22.
Friday
A 30 percent chance of snow before 1pm. Partly sunny, with a high near 33.
Friday Night
Partly cloudy, with a low around 24.
Saturday
Mostly sunny, with a high near 39.
Saturday Night
Mostly cloudy, with a low around 27.
Sunday
A 30 percent chance of snow showers. Partly sunny, with a high near 36.
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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:
1:57 am EST Jan 12, 2026
Forecast Valid:
4am EST Jan 12, 2026-6pm EST Jan 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