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

73°F

23°C

Humidity 81%
Wind Speed N 7 mph
Barometer 29.79 in (1008.7 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 12 Aug 4:56 am EDT
Extended Forecast for

Islip NY

  • Overnight

    Overnight: A 20 percent chance of showers. Mostly cloudy, with a low around 72. North wind around 6 mph.

    Low: 72 °F

    Slight Chance
    Showers

  • Wednesday

    Wednesday: Mostly cloudy through mid morning, then gradual clearing, with a high near 87. North wind 5 to 7 mph.

    High: 87 °F

    Becoming
    Sunny

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly between 2am and 5am. Increasing clouds, with a low around 72. Southwest wind around 6 mph.

    Low: 72 °F

    Mostly Clear
    then Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers and thunderstorms before 11am, then a slight chance of showers and thunderstorms after 2pm. Increasing clouds, with a high near 85. Southwest wind 5 to 9 mph. Chance of precipitation is 20%.

    High: 85 °F

    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 67. Southwest wind around 5 mph becoming light and variable in the evening.

    Low: 67 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 67.

    Low: 67 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 80.

    High: 80 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 66.

    Low: 66 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 20 percent chance of showers. Mostly cloudy, with a low around 72. North wind around 6 mph.
Wednesday
Mostly cloudy through mid morning, then gradual clearing, with a high near 87. North wind 5 to 7 mph.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly between 2am and 5am. Increasing clouds, with a low around 72. Southwest wind around 6 mph.
Thursday
A slight chance of showers and thunderstorms before 11am, then a slight chance of showers and thunderstorms after 2pm. Increasing clouds, with a high near 85. Southwest wind 5 to 9 mph. Chance of precipitation is 20%.
Thursday Night
Partly cloudy, with a low around 67. Southwest wind around 5 mph becoming light and variable in the evening.
Friday
Mostly sunny, with a high near 83.
Friday Night
Mostly clear, with a low around 67.
Saturday
Sunny, with a high near 80.
Saturday Night
Partly cloudy, with a low around 66.
Sunday
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 82.
Sunday Night
Showers likely. Mostly cloudy, with a low around 69. Chance of precipitation is 70%.
Monday
A 40 percent chance of showers. Partly sunny, with a high near 83.
Monday Night
Partly cloudy, with a low around 66.
Tuesday
Sunny, with a high near 83.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip NY
 40.73°N 73.22°W (Elev. 7 ft)
Last Update:
2:24 am EDT Aug 12, 2026
Forecast Valid:
5am EDT Aug 12, 2026-6pm EDT Aug 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