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

65°F

18°C

Humidity 66%
Wind Speed SW 3 mph
Barometer 29.90 in (1012.5 mb)
Dewpoint 53°F (12°C)
Visibility 10.00 mi
Last update 14 Apr 11:56 pm EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Overnight

    Overnight: Partly cloudy, with a low around 55. Southwest wind 6 to 8 mph.

    Low: 55 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 79. Southwest wind 6 to 13 mph.

    High: 79 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 57. Southwest wind 6 to 9 mph. Chance of precipitation is 30%.

    Low: 57 °F

    Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: Partly sunny, with a high near 77. Southwest wind 6 to 11 mph.

    High: 77 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: A 20 percent chance of showers after 2am. Mostly cloudy, with a low around 55. Southwest wind 5 to 10 mph.

    Low: 55 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Friday

    Friday: A 40 percent chance of showers after 2pm. Partly sunny, with a high near 71.

    High: 71 °F

    Partly Sunny
    then Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 50.

    Low: 50 °F

    Chance
    Showers then
    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 62.

    High: 62 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 48.

    Low: 48 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Partly cloudy, with a low around 55. Southwest wind 6 to 8 mph.
Wednesday
Mostly sunny, with a high near 79. Southwest wind 6 to 13 mph.
Wednesday Night
A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 57. Southwest wind 6 to 9 mph. Chance of precipitation is 30%.
Thursday
Partly sunny, with a high near 77. Southwest wind 6 to 11 mph.
Thursday Night
A 20 percent chance of showers after 2am. Mostly cloudy, with a low around 55. Southwest wind 5 to 10 mph.
Friday
A 40 percent chance of showers after 2pm. Partly sunny, with a high near 71.
Friday Night
A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 50.
Saturday
Partly sunny, with a high near 62.
Saturday Night
Mostly cloudy, with a low around 48.
Sunday
A 50 percent chance of showers after 8am. Mostly cloudy, with a high near 61.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 40.
Monday
Mostly sunny, with a high near 52.
Monday Night
Mostly clear, with a low around 34.
Tuesday
Sunny, with a high near 52.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
9:09 pm EDT Apr 14, 2026
Forecast Valid:
12am 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