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

73°F

23°C

Humidity 94%
Wind Speed SW 5 mph
Barometer 30.05 in (1017.5 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Last update 7 Aug 11:56 pm EDT
Extended Forecast for

Islip Terrace NY

Heat Advisory August 8, 12:29am until August 8, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 8, 12:29am until August 8, 08:00pm

    NOW until 8:00pm Sat

    Heat Advisory

  • Overnight

    Low: 74 °F

    Slight Chance
    Showers

  • Saturday

    Saturday: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Mostly sunny, with a high near 88. Heat index values as high as 97. Southwest wind 6 to 11 mph.

    High: 88 °F

    Mostly Sunny
    then Chance
    T-storms

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms before 11pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 74. Southwest wind 3 to 7 mph.

    Low: 74 °F

    Chance
    T-storms then
    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 89. Heat index values as high as 97. West wind 5 to 9 mph.

    High: 89 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 72. West wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 74.

    Low: 74 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 40 percent chance of showers after 2pm. Partly sunny, with a high near 89.

    High: 89 °F

    Mostly Sunny
    then Chance
    Showers

Detailed Forecast

Overnight
A 20 percent chance of showers before 2am. Mostly cloudy, with a low around 74. Light west wind.
Saturday
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Mostly sunny, with a high near 88. Heat index values as high as 97. Southwest wind 6 to 11 mph.
Saturday Night
A 30 percent chance of showers and thunderstorms before 11pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 74. Southwest wind 3 to 7 mph.
Sunday
Sunny, with a high near 89. Heat index values as high as 97. West wind 5 to 9 mph.
Sunday Night
Mostly clear, with a low around 72. West wind around 5 mph becoming calm in the evening.
Monday
Sunny, with a high near 87.
Monday Night
Partly cloudy, with a low around 74.
Tuesday
A 40 percent chance of showers after 2pm. Partly sunny, with a high near 89.
Tuesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 72.
Wednesday
Partly sunny, with a high near 85.
Wednesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 70.
Thursday
Mostly sunny, with a high near 85.
Thursday Night
Partly cloudy, with a low around 68.
Friday
Mostly sunny, with a high near 83.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip Terrace NY
 40.77°N 73.18°W (Elev. 49 ft)
Last Update:
8:49 pm EDT Aug 7, 2026
Forecast Valid:
12am EDT Aug 8, 2026-6pm EDT Aug 14, 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