National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

81°F

27°C

Humidity 57%
Wind Speed SW 6 mph
Barometer 29.89 in (1012.1 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 19 Aug 5:56 pm EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Tonight

    Tonight: Mostly clear, with a low around 70. Southwest wind 5 to 10 mph.

    Low: 70 °F

    Mostly Clear

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 5pm. Increasing clouds, with a high near 82. North wind 5 to 7 mph becoming south in the afternoon. Chance of precipitation is 30%.

    High: 82 °F

    Chance
    Showers

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely before 11pm, then a chance of showers. Mostly cloudy, with a low around 65. Northeast wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 65 °F

    Showers
    Likely

  • Friday

    Friday: A 40 percent chance of showers. Partly sunny, with a high near 80. East wind around 10 mph.

    High: 80 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 65. East wind 6 to 8 mph.

    Low: 65 °F

    Chance
    Showers

  • Saturday

    Saturday: Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 79. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 79 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms, then showers likely after 8pm. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely

  • Sunday

    Sunday: A 30 percent chance of showers after 2pm. Partly sunny, with a high near 82.

    High: 82 °F

    Mostly Cloudy
    then Chance
    Showers

  • Sunday Night

    Sunday Night: A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers then
    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 70. Southwest wind 5 to 10 mph.
Thursday
A chance of showers, with thunderstorms also possible after 5pm. Increasing clouds, with a high near 82. North wind 5 to 7 mph becoming south in the afternoon. Chance of precipitation is 30%.
Thursday Night
Showers and thunderstorms likely before 11pm, then a chance of showers. Mostly cloudy, with a low around 65. Northeast wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 80. East wind around 10 mph.
Friday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 65. East wind 6 to 8 mph.
Saturday
Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 79. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Saturday Night
A chance of showers and thunderstorms, then showers likely after 8pm. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.
Sunday
A 30 percent chance of showers after 2pm. Partly sunny, with a high near 82.
Sunday Night
A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 65.
Monday
Sunny, with a high near 81.
Monday Night
Mostly clear, with a low around 63.
Tuesday
Sunny, with a high near 80.
Tuesday Night
Partly cloudy, with a low around 64.
Wednesday
Mostly sunny, with a high near 81.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
2:29 pm EDT Aug 19, 2026
Forecast Valid:
6pm EDT Aug 19, 2026-6pm EDT Aug 26, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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