Grand Canyon National Park‘s Grand Canyon heat warning has been extended through the weekend, with the National Park Service (NPS) telling visitors to stay off trails between 10 a.m. and 4 p.m. daily from Thursday, 31 July through to Sunday, 3 August, as rim temperatures approach 100°F/38°C and Inner Canyon conditions are expected to climb well beyond that.
The warning follows a summer already marked by multiple visitor fatalities. Four people have died in three separate heat-related incidents since June, and the NPS has made clear that further deaths remain a real risk while extreme temperatures persist.
Grand Canyon Heat Warning: What the NPS Is Telling Visitors
The park’s official Instagram account framed the guidance plainly: ‘Be smart; hike early in the morning, or in the later evening hours. Completely avoid hiking between the hours of 10 a.m.–4 p.m.’ The National Weather Service (NWS) has issued an Extreme Heat Warning for the Grand Canyon area, currently scheduled to end at 8 p.m. local time. Conditions during the six-hour window the NPS wants hikers off the trails include highs of near 113°F on Friday, rising to near 115°F on Saturday and Sunday, with overnight lows holding around 78°F throughout.
Sunday brings an added wind factor, with south-westerly gusts of up to 22 mph forecast during the day and gusts up to 17 mph overnight. The NWS also anticipates a high of near 114°F on Monday before gradually cooling temperatures and chances of showers arrive from Wednesday onward.
Standard heat safety advice from the NPS for those hiking outside the restricted window includes drinking plenty of water, replacing salts with salty snacks, wearing sun protection, planning for shorter outdoor activities, carrying a flashlight or headlamp to wait out the heat, and getting clothes wet to cool down.
The Grand Canyon Conservancy has added its voice to the safety messaging. ‘All visitors to the Grand Canyon should ensure they are drinking plenty of fluids, resting in shade during the heat of the day, and dressing appropriately for the weather, which includes loose-fitting cotton clothing,’ the organisation’s dress code warning reads.
Four Deaths in Three Incidents Since June
The backdrop to this weekend’s Grand Canyon heat warning is a summer that has already cost four lives. The first fatality occurred on 3 June, when an 18-year-old hiker died on the Bright Angel Trail after exhibiting heat-related symptoms. According to the National Park Service, the Grand Canyon Regional Communications Center received reports of the hiker at approximately 1:40 p.m. Rangers located the individual approximately 30 feet below the trail in a remote area near Garden Creek. The Bright Angel Trail, as Outside Online notes, runs roughly eight miles from the South Rim to the Colorado River and descends 4,500 feet, a combination that makes the return climb particularly punishing in mid-afternoon heat.
A 72-year-old man died on 12 June on the South Kaibab Trail in the Inner Canyon, where temperatures can exceed 109°F in the shade during midday hours. Two weeks later, on 16 June, a 67-year-old man and a 68-year-old woman lost their lives on the North Kaibab Trail, also in the Inner Canyon. ‘Despite rapid response and aerial support, all three individuals were found deceased when responders arrived,’ the park said of both incidents, adding that ‘conditions can quickly overwhelm hikers during the hottest parts of the day.’
The Inner Canyon deaths are consistent with a longer pattern. Grand Canyon ranks second among all NPS sites in terms of total fatalities, according to a report by MyBaggage, which analysed NPS data, with an average of 12.7 deaths per year. Approximately 900 people have died in the canyon since the 1800s. By way of comparison, Lake Mead National Recreation Area ranks first, recording 317 deaths between 2007 and 2024, an average of 20.88 per year.
Across the entire NPS system, park fatalities remain low relative to visitor numbers. Fewer than 200 deaths were recorded at NPS sites in 2025, according to the National Parks Traveler, representing around 0.00006% of all park visitors. Approximately three out of four of those deaths occurred between May and September, with July accounting for more than 21% of all 2025 fatalities. Eighty-four per cent of those who died were men.
With the NWS forecast showing unrelenting sunny and hot conditions through Sunday night, the NPS’s 10 a.m.–4 p.m. exclusion window is the operative guidance for anyone planning to be on trail this weekend.
