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.

Mostly Cloudy

58°F

14°C

Humidity 87%
Wind Speed Calm
Barometer 29.90 in (1012.3 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Last update 15 Apr 5:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Today

    Today: Mostly sunny, with a high near 82. Calm wind becoming south 5 to 9 mph in the morning.

    High: 82 °F

    Mostly Sunny

  • Tonight

    Tonight: A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph. Chance of precipitation is 40%.

    Low: 54 °F

    Chance
    T-storms

  • Thursday

    Thursday: Partly sunny, with a high near 80. Light southwest wind becoming south 5 to 9 mph in the morning.

    High: 80 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 54. Southwest wind around 6 mph.

    Low: 54 °F

    Mostly Cloudy

  • Friday

    Friday: A chance of showers, with thunderstorms also possible after 5pm. Partly sunny, with a high near 74. West wind 3 to 7 mph. Chance of precipitation is 40%.

    High: 74 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 51.

    Low: 51 °F

    Chance
    Showers then
    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 61.

    High: 61 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 46.

    Low: 46 °F

    Mostly Cloudy

  • Sunday

    Sunday: Showers likely, mainly after 2pm. Mostly cloudy, with a high near 59. Chance of precipitation is 60%.

    High: 59 °F

    Showers
    Likely

Detailed Forecast

Today
Mostly sunny, with a high near 82. Calm wind becoming south 5 to 9 mph in the morning.
Tonight
A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph. Chance of precipitation is 40%.
Thursday
Partly sunny, with a high near 80. Light southwest wind becoming south 5 to 9 mph in the morning.
Thursday Night
Mostly cloudy, with a low around 54. Southwest wind around 6 mph.
Friday
A chance of showers, with thunderstorms also possible after 5pm. Partly sunny, with a high near 74. West wind 3 to 7 mph. Chance of precipitation is 40%.
Friday Night
A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 51.
Saturday
Partly sunny, with a high near 61.
Saturday Night
Mostly cloudy, with a low around 46.
Sunday
Showers likely, mainly after 2pm. Mostly cloudy, with a high near 59. Chance of precipitation is 60%.
Sunday Night
Showers likely, mainly before 8pm. Mostly cloudy, with a low around 39. Chance of precipitation is 60%.
Monday
Mostly sunny, with a high near 51.
Monday Night
Mostly clear, with a low around 35.
Tuesday
Sunny, with a high near 53.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.8°N 73.09°W (Elev. 98 ft)
Last Update:
5:23 am EDT Apr 15, 2026
Forecast Valid:
6am EDT Apr 15, 2026-6pm EDT Apr 21, 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