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

79°F

26°C

Humidity 90%
Wind Speed Calm
Barometer 29.93 in (1013.3 mb)
Dewpoint 76°F (24°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 25 Jul 8:56 pm EDT
Extended Forecast for

Islip NY

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms before 11pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 73. Light and variable wind becoming north around 5 mph after midnight.

    Low: 73 °F

    Slight Chance
    T-storms then
    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 84. Northeast wind around 10 mph becoming southeast in the afternoon.

    High: 84 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 71. South wind 3 to 7 mph.

    Low: 71 °F

    Mostly Cloudy

  • Sunday

    Sunday: A 50 percent chance of showers and thunderstorms, mainly after 8am. Mostly cloudy, with a high near 80. South wind 6 to 10 mph.

    High: 80 °F

    Chance
    Showers then
    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 30 percent chance of showers and thunderstorms, mainly before 11pm. Mostly cloudy, with a low around 71. Southwest wind 5 to 7 mph becoming calm after midnight.

    Low: 71 °F

    Chance
    T-storms

  • Monday

    Monday: Sunny, with a high near 88.

    High: 88 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 73.

    Low: 73 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 91.

    High: 91 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 75.

    Low: 75 °F

    Mostly Clear

Detailed Forecast

Tonight
A 20 percent chance of showers and thunderstorms before 11pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 73. Light and variable wind becoming north around 5 mph after midnight.
Saturday
Mostly sunny, with a high near 84. Northeast wind around 10 mph becoming southeast in the afternoon.
Saturday Night
Mostly cloudy, with a low around 71. South wind 3 to 7 mph.
Sunday
A 50 percent chance of showers and thunderstorms, mainly after 8am. Mostly cloudy, with a high near 80. South wind 6 to 10 mph.
Sunday Night
A 30 percent chance of showers and thunderstorms, mainly before 11pm. Mostly cloudy, with a low around 71. Southwest wind 5 to 7 mph becoming calm after midnight.
Monday
Sunny, with a high near 88.
Monday Night
Mostly clear, with a low around 73.
Tuesday
Sunny, with a high near 91.
Tuesday Night
Mostly clear, with a low around 75.
Wednesday
Sunny, with a high near 90.
Wednesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 71.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 83.
Thursday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 67.
Friday
Mostly sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip NY
 40.73°N 73.25°W (Elev. 13 ft)
Last Update:
8:01 pm EDT Jul 25, 2025
Forecast Valid:
9pm EDT Jul 25, 2025-6pm EDT Aug 1, 2025
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation