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

82°F

28°C

Humidity 65%
Wind Speed N 7 mph
Barometer 29.84 in (1010.2 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index85°F (29°C)
Last update 11 Aug 11:56 am EDT
Extended Forecast for

Islip NY

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87. West wind 7 to 10 mph.

    High: 87 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A slight chance of showers and thunderstorms, then a chance of showers after 2am. Partly cloudy, with a low around 71. West wind around 6 mph becoming light and variable. Chance of precipitation is 30%.

    Low: 71 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Wednesday

    Wednesday: A 30 percent chance of showers, mainly before 8am. Mostly sunny, with a high near 86. North wind 5 to 7 mph becoming west in the afternoon.

    High: 86 °F

    Chance
    Showers then
    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 70. South wind 3 to 6 mph.

    Low: 70 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 85. Southwest wind 5 to 10 mph.

    High: 85 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers before 8pm, then a chance of showers after 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 30%.

    Low: 71 °F

    Chance
    Showers

  • Friday

    Friday: A 30 percent chance of showers before 8am. Sunny, with a high near 85.

    High: 85 °F

    Chance
    Showers then
    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87. West wind 7 to 10 mph.
Tonight
A slight chance of showers and thunderstorms, then a chance of showers after 2am. Partly cloudy, with a low around 71. West wind around 6 mph becoming light and variable. Chance of precipitation is 30%.
Wednesday
A 30 percent chance of showers, mainly before 8am. Mostly sunny, with a high near 86. North wind 5 to 7 mph becoming west in the afternoon.
Wednesday Night
Partly cloudy, with a low around 70. South wind 3 to 6 mph.
Thursday
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 85. Southwest wind 5 to 10 mph.
Thursday Night
A chance of showers before 8pm, then a chance of showers after 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 30%.
Friday
A 30 percent chance of showers before 8am. Sunny, with a high near 85.
Friday Night
Mostly clear, with a low around 63.
Saturday
Sunny, with a high near 81.
Saturday Night
Partly cloudy, with a low around 64.
Sunday
Mostly sunny, with a high near 80.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 68.
Monday
A 40 percent chance of showers. Partly sunny, with a high near 80.
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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:
3:05 am EDT Aug 11, 2026
Forecast Valid:
12pm EDT Aug 11, 2026-6pm EDT Aug 17, 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