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.

Thunderstorm Heavy Rain Fog/Mist

69°F

21°C

Humidity 93%
Wind Speed SW 7 mph
Barometer 30.05 in (1017.4 mb)
Dewpoint 67°F (19°C)
Visibility 1.50 mi
Last update 1 Jul 5:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

Extreme Heat Watch July 3, 09:00pm until July 4, 09:00pm
Extreme Heat Warning July 1, 12:00pm until July 3, 09:00pm
Click here for hazard details and duration
Extreme Heat Watch
Extreme Heat Warning

  • Today

    Today: A 20 percent chance of showers and thunderstorms before 8am. Mostly sunny, with a high near 86. Southwest wind 10 to 14 mph.

    High: 86 °F

    Slight Chance
    T-storms then
    Sunny

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 72. Southwest wind 10 to 13 mph, with gusts as high as 23 mph.

    Low: 72 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: Sunny, with a high near 93. Heat index values as high as 102. Southwest wind 7 to 11 mph.

    High: 93 °F

    Sunny

  • Thursday Night

    Thursday Night: Clear, with a low around 77. Southwest wind 5 to 10 mph becoming light after midnight.

    Low: 77 °F

    Clear

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 2pm. Sunny and hot, with a high near 100. West wind 5 to 10 mph.

    High: 100 °F

    Sunny then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: Partly cloudy, with a low around 77.

    Low: 77 °F

    Partly Cloudy

  • Independence Day

    Independence Day: A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 96.

    High: 96 °F

    Sunny then
    Chance
    Showers

  • Saturday Night

    Saturday Night: A 40 percent chance of showers before 2am. Mostly cloudy, with a low around 74.

    Low: 74 °F

    Chance
    Showers

  • Sunday

    Sunday: A 30 percent chance of showers after 2pm. Partly sunny, with a high near 88.

    High: 88 °F

    Partly Sunny
    then Chance
    Showers

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms before 8am. Mostly sunny, with a high near 86. Southwest wind 10 to 14 mph.
Tonight
A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 72. Southwest wind 10 to 13 mph, with gusts as high as 23 mph.
Thursday
Sunny, with a high near 93. Heat index values as high as 102. Southwest wind 7 to 11 mph.
Thursday Night
Clear, with a low around 77. Southwest wind 5 to 10 mph becoming light after midnight.
Friday
A 20 percent chance of showers and thunderstorms after 2pm. Sunny and hot, with a high near 100. West wind 5 to 10 mph.
Friday Night
Partly cloudy, with a low around 77.
Independence Day
A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 96.
Saturday Night
A 40 percent chance of showers before 2am. Mostly cloudy, with a low around 74.
Sunday
A 30 percent chance of showers after 2pm. Partly sunny, with a high near 88.
Sunday Night
A chance of showers before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 70%.
Monday
A 50 percent chance of showers. Mostly cloudy, with a high near 85.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 69.
Tuesday
Mostly sunny, with a high near 84.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.78°N 73.09°W (Elev. 49 ft)
Last Update:
2:37 am EDT Jul 1, 2026
Forecast Valid:
6am EDT Jul 1, 2026-6pm EDT Jul 7, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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