Flagstaff, Ariz. – Day hikers in Grand Canyon National Park face life-threatening heat this week as temperatures soar past 110°F in the inner canyon, with a warning in effect until 7 p.m. Friday for areas below 4,000 feet.
According to the National Weather Service in Flagstaff, dangerously hot conditions will persist across lower elevations such as Havasupai Gardens (104°F) and Phantom Ranch (114°F). The Extreme Heat Warning, rarely issued, signals some of the hottest days of the year, prompting urgent safety guidance for visitors.
Hikers on the Bright Angel Trail are advised not to descend more than 1.5 miles from the rim. Between 10 a.m. and 4 p.m., outdoor activity is strongly discouraged unless hikers are stationed at Havasupai Gardens or campgrounds with proper shelter. Without cooling, hydration, salty snacks, and electrolyte mix, heat-related illnesses can set in quickly.
Park rangers urge visitors to hike early or not at all, wear wide-brimmed hats and sunscreen, and double caloric intake to maintain energy under extreme heat stress.
The warning remains in place through Friday, and additional advisories may follow if temperatures remain elevated into the weekend.
