National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Dangerous Heat and Possible Flooding

Dangerous heat will persist across the Southwest U.S. through Saturday with daytime highs of 110-115°F. Extreme Heat Warnings remain in effect. Dangerous heat will build across the southern Plains again beginning this weekend. Heavy to excessive rain over the Carolinas Friday may lead to isolated areas of flash flooding. Read More >

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fair

67°F

19°C

Humidity 68%
Wind Speed N 14 mph
Barometer 30.12 in (1019.9 mb)
Dewpoint 56°F (13°C)
Visibility 10.00 mi
Last update 29 Aug 2:56 am EDT
Extended Forecast for

Islandia NY

  • Overnight

    Overnight: Mostly clear, with a low around 61. North wind around 8 mph.

    Low: 61 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 77. North wind 3 to 8 mph.

    High: 77 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 61. Light southwest wind.

    Low: 61 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 80. Light southwest wind increasing to 6 to 11 mph in the morning.

    High: 80 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A 50 percent chance of showers, mainly after 8pm. Partly cloudy during the early evening, then becoming cloudy, with a low around 67. West wind 5 to 9 mph.

    Low: 67 °F

    Chance
    Showers

  • Monday

    Monday: Partly sunny, with a high near 81.

    High: 81 °F

    Partly Sunny

  • Monday Night

    Monday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A 50 percent chance of showers. Mostly cloudy, with a high near 78.

    High: 78 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely

Detailed Forecast

Overnight
Mostly clear, with a low around 61. North wind around 8 mph.
Saturday
Mostly sunny, with a high near 77. North wind 3 to 8 mph.
Saturday Night
Mostly clear, with a low around 61. Light southwest wind.
Sunday
Mostly sunny, with a high near 80. Light southwest wind increasing to 6 to 11 mph in the morning.
Sunday Night
A 50 percent chance of showers, mainly after 8pm. Partly cloudy during the early evening, then becoming cloudy, with a low around 67. West wind 5 to 9 mph.
Monday
Partly sunny, with a high near 81.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 65.
Tuesday
A 50 percent chance of showers. Mostly cloudy, with a high near 78.
Tuesday Night
Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.
Wednesday
A chance of showers before 8am, then a chance of showers after 2pm. Mostly cloudy, with a high near 80. Chance of precipitation is 30%.
Wednesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 67. Chance of precipitation is 60%.
Thursday
A 40 percent chance of showers. Partly sunny, with a high near 83.
Thursday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 64.
Friday
Mostly sunny, with a high near 78.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islandia NY
 40.81°N 73.17°W (Elev. 161 ft)
Last Update:
2:28 am EDT Aug 29, 2026
Forecast Valid:
3am EDT Aug 29, 2026-6pm EDT Sep 4, 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