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

78°F

26°C

Humidity 45%
Wind Speed N 8 mph
Barometer 30.21 in (1022.8 mb)
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 8 Sep 3:56 pm EDT
Extended Forecast for

Islip NY

  • Tonight

    Tonight: Partly cloudy, with a low around 66. Southwest wind around 5 mph becoming calm in the evening.

    Low: 66 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 81. Light southwest wind becoming south 10 to 15 mph in the morning.

    High: 81 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 72. Southwest wind 16 to 18 mph, with gusts as high as 30 mph.

    Low: 72 °F

    Partly Cloudy

  • Thursday

    Thursday: A chance of showers between 2pm and 5pm, then a chance of showers and thunderstorms after 5pm. Partly sunny, with a high near 85. Southwest wind 11 to 14 mph. Chance of precipitation is 40%.

    High: 85 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 66. West wind around 7 mph becoming northwest after midnight. Chance of precipitation is 50%.

    Low: 66 °F

    Chance
    Showers

  • Friday

    Friday: Partly sunny, then gradually becoming sunny, with a high near 77.

    High: 77 °F

    Becoming
    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 62.

    Low: 62 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 77.

    High: 77 °F

    Mostly Sunny

  • Saturday Night

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

    Low: 66 °F

    Partly Cloudy

Detailed Forecast

Tonight
Partly cloudy, with a low around 66. Southwest wind around 5 mph becoming calm in the evening.
Wednesday
Mostly sunny, with a high near 81. Light southwest wind becoming south 10 to 15 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 72. Southwest wind 16 to 18 mph, with gusts as high as 30 mph.
Thursday
A chance of showers between 2pm and 5pm, then a chance of showers and thunderstorms after 5pm. Partly sunny, with a high near 85. Southwest wind 11 to 14 mph. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 66. West wind around 7 mph becoming northwest after midnight. Chance of precipitation is 50%.
Friday
Partly sunny, then gradually becoming sunny, with a high near 77.
Friday Night
Mostly clear, with a low around 62.
Saturday
Mostly sunny, with a high near 77.
Saturday Night
Partly cloudy, with a low around 66.
Sunday
A 30 percent chance of showers after 8am. Partly sunny, with a high near 80.
Sunday Night
Mostly cloudy, with a low around 67.
Monday
Mostly sunny, with a high near 80.
Monday Night
Partly cloudy, with a low around 64.
Tuesday
Mostly sunny, with a high near 77.
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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:
2:19 pm EDT Sep 8, 2026
Forecast Valid:
4pm EDT Sep 8, 2026-6pm EDT Sep 15, 2026
 
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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