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.

Light Snow Fog/Mist

33°F

1°C

Humidity 96%
Wind Speed W 7 mph
Barometer 29.86 in (1011.3 mb)
Dewpoint 32°F (0°C)
Visibility 1.50 mi
Wind Chill27°F (-3°C)
Last update 12 Mar 6:56 pm EDT
Extended Forecast for

Head of the Harbor NY

  • Tonight

    Tonight: Snow before 8pm. Low around 30. Northwest wind 10 to 13 mph. Chance of precipitation is 90%. Total nighttime snow accumulation of less than a half inch possible.

    Low: 30 °F

    Snow then
    Mostly Clear

  • Friday

    Friday: Increasing clouds, with a high near 46. West wind 5 to 14 mph becoming south in the afternoon.

    High: 46 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 37. South wind 13 to 15 mph, with gusts as high as 31 mph.

    Low: 37 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 49. West wind around 18 mph, with gusts as high as 31 mph.

    High: 49 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 32. Northwest wind 5 to 10 mph becoming light after midnight. Winds could gust as high as 20 mph.

    Low: 32 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 48.

    High: 48 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Rain, mainly after 2am. Low around 40. Chance of precipitation is 80%.

    Low: 40 °F

    Chance Rain
    then Rain

  • Monday

    Monday: Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.

    High: 56 °F

    Rain and
    Breezy

  • Monday Night

    Monday Night: Rain, mainly before 2am. Low around 35. Breezy. Chance of precipitation is 80%.

    Low: 35 °F

    Rain and
    Breezy

Detailed Forecast

Tonight
Snow before 8pm. Low around 30. Northwest wind 10 to 13 mph. Chance of precipitation is 90%. Total nighttime snow accumulation of less than a half inch possible.
Friday
Increasing clouds, with a high near 46. West wind 5 to 14 mph becoming south in the afternoon.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 37. South wind 13 to 15 mph, with gusts as high as 31 mph.
Saturday
Sunny, with a high near 49. West wind around 18 mph, with gusts as high as 31 mph.
Saturday Night
Increasing clouds, with a low around 32. Northwest wind 5 to 10 mph becoming light after midnight. Winds could gust as high as 20 mph.
Sunday
Mostly cloudy, with a high near 48.
Sunday Night
Rain, mainly after 2am. Low around 40. Chance of precipitation is 80%.
Monday
Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.
Monday Night
Rain, mainly before 2am. Low around 35. Breezy. Chance of precipitation is 80%.
Tuesday
A 30 percent chance of rain before 8am. Mostly sunny, with a high near 44.
Tuesday Night
Partly cloudy, with a low around 25.
Wednesday
Sunny, with a high near 38.
Wednesday Night
Partly cloudy, with a low around 28.
Thursday
Partly sunny, with a high near 42.
Basemap Options
Click map to change the forecast location
Loading map...
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:
6:03 pm EDT Mar 12, 2026
Forecast Valid:
7pm EDT Mar 12, 2026-6pm EDT Mar 19, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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