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

Dangerous Heat in the Central and Eastern U.S.; Critical Fire Weather in the Great Basin and Southwest

Dangerous, record-breaking heat will intensify across most of the central and eastern U.S this week. Heat indices will likely exceed 100 degrees. Heat is likely to continue across the eastern U.S. through the Independence Day holiday weekend. Critical fire weather conditions will continue Tuesday across portions of the Four Corners and Great Basin, as dry conditions and gusty winds persist. Read More >

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fair

68°F

20°C

Humidity 81%
Wind Speed SW 5 mph
Barometer 30.12 in (1019.7 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Last update 30 Jun 1:56 am EDT
Extended Forecast for

Islip NY

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

  • Overnight

    Overnight: Patchy fog before 3am. Otherwise, partly cloudy, with a low around 66. Light southwest wind.

    Low: 66 °F

    Patchy Fog

  • Tuesday

    Tuesday: Patchy fog before 7am. Otherwise, mostly sunny, with a high near 82. Southwest wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 82 °F

    Patchy Fog
    then Mostly
    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms after 11pm. Partly cloudy, with a low around 70. Southwest wind 10 to 18 mph, with gusts as high as 28 mph.

    Low: 70 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: Mostly sunny, with a high near 88. Southwest wind 10 to 17 mph.

    High: 88 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 73. Southwest wind 9 to 13 mph.

    Low: 73 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: Sunny, with a high near 95.

    High: 95 °F

    Sunny

  • Thursday Night

    Thursday Night: Clear, with a low around 77.

    Low: 77 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 97.

    High: 97 °F

    Sunny

  • Friday Night

    Friday Night: A chance of showers between 8pm and 2am. Partly cloudy, with a low around 75. Chance of precipitation is 30%.

    Low: 75 °F

    Chance
    Showers

Detailed Forecast

Overnight
Patchy fog before 3am. Otherwise, partly cloudy, with a low around 66. Light southwest wind.
Tuesday
Patchy fog before 7am. Otherwise, mostly sunny, with a high near 82. Southwest wind 5 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
A 20 percent chance of showers and thunderstorms after 11pm. Partly cloudy, with a low around 70. Southwest wind 10 to 18 mph, with gusts as high as 28 mph.
Wednesday
Mostly sunny, with a high near 88. Southwest wind 10 to 17 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 73. Southwest wind 9 to 13 mph.
Thursday
Sunny, with a high near 95.
Thursday Night
Clear, with a low around 77.
Friday
Sunny, with a high near 97.
Friday Night
A chance of showers between 8pm and 2am. Partly cloudy, with a low around 75. Chance of precipitation is 30%.
Independence Day
A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 95.
Saturday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 73.
Sunday
Mostly sunny, with a high near 91.
Sunday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 72.
Monday
A 30 percent chance of showers. Partly sunny, with a high near 88.
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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:
3:53 pm EDT Jun 29, 2026
Forecast Valid:
2am EDT Jun 30, 2026-6pm EDT Jul 6, 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