Extreme Heat Warning issued August 17 at 9:28PM MST until August 20 at 8:00PM MST by NWS Flagstaff AZ

  • WHAT...Dangerously hot conditions expected below 4000 feet, with daytime temperatures ranging from 94 to 99 degrees at Havasupai Gardens, and 107 to 111 degrees at Phantom Ranch. * WHERE...Lower elevations of the Grand Canyon. * WHEN...From 10 AM Tuesday to 8 PM MST Thursday. * IMPACTS...Most individuals will be at risk for heat-related illnesses without effective cooling or adequate hydration, especially with prolonged outdoor exposure.

What 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.

Issued by NWS Flagstaff AZ; in effect until Fri, 21 Aug 2026 03:00:00 GMT.

Source: National Weather Service (NOAA). Factual summary of a public release; not financial advice.

AI-assisted report. Disclosed per Moondial News integrity policy.