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Extreme Heat Warning for Grand Canyon Country

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What is happening

What: Dangerously hot conditions expected below 4000 feet, with daytime temperatures ranging from 103 to 108 degrees at Havasupai Gardens, and 111 to 115 degrees at Phantom Ranch. Impacts: Most individuals will be at risk for heat-related illnesses without effective cooling or adequate hydration, especially with...

What the bulletin says to do

This warning is reserved for only the hottest days of the year and is issued when temperatures are expected to rise to dangerous levels. Day hikers on Bright Angel Trail should descend no farther than 1 1/2 miles from the upper trailhead. Between the hours of 10 AM and 4 PM, hikers should be out of the canyon or at Havasupai Gardens or Bright Angel campgrounds, physical activity is discouraged. All hikers should have adequate gear, including a wide-brimmed hat, sunscreen, salty snacks, sufficient water, and electrolyte mix. Doubling your calorie intake helps maintain your energy. Hike smart.

Read official NWS bulletin

Full official description

Bulletin details

* WHAT...Dangerously hot conditions expected below 4000 feet, with daytime temperatures ranging from 103 to 108 degrees at Havasupai Gardens, and 111 to 115 degrees at Phantom Ranch. * WHERE...Lower elevations of the Grand Canyon. * WHEN...Until 8 PM MST Tuesday. * IMPACTS...Most individuals will be at risk for heat-related illnesses without effective cooling or adequate hydration, especially with prolonged outdoor exposure.

Official geometry where available

Alert boundary

Lifecycle record

Official revisions

26 captured
  1. Update

    Extreme Heat Warning issued August 1 at 11:27AM MST until August 3 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  2. Update

    Extreme Heat Warning issued August 1 at 11:27AM MST until August 3 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  3. Update

    Extreme Heat Warning issued August 1 at 11:27AM MST until August 4 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  4. Update

    Extreme Heat Warning issued July 31 at 10:34PM MST until August 4 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  5. Update

    Extreme Heat Warning issued July 31 at 10:34PM MST until August 3 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  6. Update

    Extreme Heat Warning issued July 31 at 10:34PM MST until August 3 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  7. Update

    Extreme Heat Warning issued July 31 at 11:31AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  8. Update

    Extreme Heat Warning issued July 31 at 11:31AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  9. Update

    Extreme Heat Warning issued July 31 at 11:31AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  10. Update

    Extreme Heat Warning issued July 30 at 10:35PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  11. Update

    Extreme Heat Warning issued July 30 at 10:35PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  12. Update

    Extreme Heat Warning issued July 30 at 10:35PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  13. Update

    Extreme Heat Warning issued July 30 at 11:48AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  14. Alert

    Extreme Heat Warning issued July 30 at 11:48AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  15. Update

    Extreme Heat Warning issued July 30 at 11:48AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  16. Update

    Extreme Heat Warning issued July 30 at 11:48AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  17. Update

    Extreme Heat Warning issued July 28 at 9:18PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  18. Update

    Extreme Heat Warning issued July 28 at 9:18PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  19. Update

    Extreme Heat Warning issued July 28 at 9:18PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  20. Alert

    Extreme Heat Warning issued July 28 at 12:15PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  21. Update

    Extreme Heat Warning issued July 28 at 12:15PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  22. Update

    Extreme Heat Warning issued July 28 at 12:15PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  23. Update

    Extreme Heat Warning issued July 28 at 12:15PM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  24. Alert

    Extreme Heat Warning issued July 27 at 11:54AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  25. Alert

    Extreme Heat Warning issued July 27 at 11:54AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision
  26. Alert

    Extreme Heat Warning issued July 27 at 11:54AM MST until August 2 at 8:00PM MST by NWS Flagstaff AZ

    Official revision

Source and limitations

Publisher: Weather Alert Watch. Primary source: NWS Flagstaff AZ. This page reorganizes official fields and does not add a forecast or expand the affected area.

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