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

71°F

22°C

Humidity 94%
Wind Speed NW 5 mph
Barometer 30.07 in (1018.2 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 31 Aug 12:56 am EDT
Extended Forecast for

Islip NY

  • Overnight

    Overnight: A 40 percent chance of showers and thunderstorms, mainly before 2am. Mostly cloudy, with a steady temperature around 70. Light west wind.

    Low: 70 °F

    Chance
    Showers

  • Monday

    Monday: A 20 percent chance of showers before 5pm. Patchy fog between 7am and 8am. Otherwise, partly sunny, with a high near 79. Light and variable wind becoming southeast 5 to 7 mph in the morning.

    High: 79 °F

    Slight Chance
    Showers and
    Patchy Fog

  • Monday Night

    Monday Night: A 40 percent chance of showers, mainly after 2am. Increasing clouds, with a low around 67. Southwest wind 3 to 5 mph.

    Low: 67 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 82. Southwest wind 5 to 9 mph. Chance of precipitation is 50%.

    High: 82 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 67. Southeast wind 3 to 6 mph. Chance of precipitation is 50%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Wednesday

    Wednesday: A 40 percent chance of showers after 2pm. Mostly cloudy, with a high near 80.

    High: 80 °F

    Mostly Cloudy
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 60%.

    Low: 68 °F

    Showers
    Likely

  • Thursday

    Thursday: A chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 83. Chance of precipitation is 40%.

    High: 83 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Overnight
A 40 percent chance of showers and thunderstorms, mainly before 2am. Mostly cloudy, with a steady temperature around 70. Light west wind.
Monday
A 20 percent chance of showers before 5pm. Patchy fog between 7am and 8am. Otherwise, partly sunny, with a high near 79. Light and variable wind becoming southeast 5 to 7 mph in the morning.
Monday Night
A 40 percent chance of showers, mainly after 2am. Increasing clouds, with a low around 67. Southwest wind 3 to 5 mph.
Tuesday
A chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 82. Southwest wind 5 to 9 mph. Chance of precipitation is 50%.
Tuesday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 67. Southeast wind 3 to 6 mph. Chance of precipitation is 50%.
Wednesday
A 40 percent chance of showers after 2pm. Mostly cloudy, with a high near 80.
Wednesday Night
A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 60%.
Thursday
A chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 83. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.
Friday
Mostly sunny, with a high near 81.
Friday Night
Partly cloudy, with a low around 63.
Saturday
Mostly sunny, with a high near 77.
Saturday Night
Partly cloudy, with a low around 60.
Sunday
Mostly sunny, with a high near 76.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip NY
 40.73°N 73.22°W (Elev. 7 ft)
Last Update:
1:16 am EDT Aug 31, 2026
Forecast Valid:
1am EDT Aug 31, 2026-6pm EDT Sep 6, 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