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

74°F

23°C

Humidity 71%
Wind Speed SE 10 mph
Barometer 30.10 in (1019.3 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 31 Aug 3:56 pm EDT
Extended Forecast for

Islip NY

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms after 5pm. Cloudy, with a high near 78. Southeast wind around 9 mph.

    High: 78 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Patchy fog after 3am. Low around 66. South wind 3 to 5 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 66 °F

    Chance
    Showers then
    Showers and
    Patchy Fog

  • Tuesday

    Tuesday: Showers likely before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers likely and possibly a thunderstorm after 5pm. Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 80. Southwest wind 3 to 7 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Showers
    Likely and
    Patchy Fog

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am, then a slight chance of showers after 2am. Mostly cloudy, with a low around 65. Northeast wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 65 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A 20 percent chance of showers before 2pm. Mostly cloudy, with a high near 77. East wind 8 to 10 mph.

    High: 77 °F

    Slight Chance
    Showers

  • Wednesday Night

    Wednesday Night: Showers likely after 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 67 °F

    Mostly Cloudy
    then Showers
    Likely

  • Thursday

    Thursday: Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 84. Chance of precipitation is 60%.

    High: 84 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.

    Low: 70 °F

    Showers
    Likely

  • Friday

    Friday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms after 5pm. Cloudy, with a high near 78. Southeast wind around 9 mph.
Tonight
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Patchy fog after 3am. Low around 66. South wind 3 to 5 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday
Showers likely before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers likely and possibly a thunderstorm after 5pm. Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 80. Southwest wind 3 to 7 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am, then a slight chance of showers after 2am. Mostly cloudy, with a low around 65. Northeast wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday
A 20 percent chance of showers before 2pm. Mostly cloudy, with a high near 77. East wind 8 to 10 mph.
Wednesday Night
Showers likely after 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Thursday
Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 84. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.
Friday
Mostly sunny, with a high near 81.
Friday Night
Partly cloudy, with a low around 65.
Saturday
Sunny, with a high near 76.
Saturday Night
Partly cloudy, with a low around 61.
Sunday
Sunny, with a high near 74.
Sunday Night
Mostly clear, with a low around 60.
Labor Day
Sunny, with a high near 75.
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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:
3:08 pm EDT Aug 31, 2026
Forecast Valid:
4pm EDT Aug 31, 2026-6pm EDT Sep 7, 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