Phoenix shattered its all-time June heat record Thursday afternoon when thermometers at Phoenix Sky Harbor International Airport climbed to 117 degrees Fahrenheit at 3:42 p.m., eclipsing the previous mark of 115 degrees set on June 26, 1994. The National Weather Service issued an Excessive Heat Warning through Sunday evening, calling the stretch the most sustained extreme-heat event the region has experienced in at least a decade.
Maricopa County Emergency Management activated its heat emergency protocols before noon, deploying mobile water stations and opening all 12 district cooling centers for extended overnight access. By 6 p.m. Thursday, county officials estimated more than 11,000 residents had checked in across those facilities. The Arizona Department of Health Services also issued an advisory urging residents to limit outdoor activity between 10 a.m. and 8 p.m.
Power Grid Holding -- For Now
Arizona Public Service and Salt River Project both reported record peak demand Thursday, but said their systems were stable. APS spokeswoman Debra Colton said the utility had prepositioned crews and activated all available generation capacity. "We are asking customers to set thermostats to 78 degrees or higher when away and to avoid running large appliances between 3 p.m. and 8 p.m.," Colton said in a written statement.
Valley Metro suspended outdoor fare enforcement and kept all light-rail and bus vehicles air-conditioned at maximum capacity, opening them as informal cooling spaces. The agency also extended service by two hours on key routes through Sunday to ensure residents without personal vehicles could reach cooling centers.
Vulnerable Populations Most at Risk
Maricopa County Medical Examiner Dr. Alejandra Portillo warned that the elderly, unhoused individuals, and outdoor workers face the greatest danger. "Heat illness can set in within minutes at these temperatures. If you see someone who appears confused, is not sweating, or has stopped responding, call 911 immediately," Portillo said at a Thursday afternoon press briefing. The county is coordinating door-to-door wellness checks for residents flagged through its senior services database.
The City of Phoenix also activated its nonprofit partnership program, directing faith-based organizations and community groups to assist with transport to cooling centers. Mayor Kate Gallego said the city was tracking conditions hourly and would extend the state of heat emergency if necessary. "We know our most vulnerable neighbors need us most right now," Gallego said. "Phoenix will get through this wave together."
Forecasters say temperatures will remain above 110 degrees through Saturday before a surge of monsoon moisture from the south may provide modest relief -- though they caution that storms can bring dangerous dust and lightning before any cooling occurs. Residents are encouraged to monitor the National Weather Service Phoenix office for updates and to sign up for Maricopa County emergency text alerts at maricopa.gov/alerts.
