Maricopa County, home to Phoenix—the fifth largest and hottest major city in the United States—continues to grapple with a severe heatwave that has raised concerns over rising mortality rates. During this unprecedented heat event, daily average temperatures in some areas exceeded 110°F (43°C) daily for the entire month of August. Sadly, the county is poised to see its hottest month ever. So far through August 11, at least one hundred and seventy daily temperature records have been broken. One of these records was a new all-time monthly high of 118°F (48°C).
Due to recent extreme weather conditions, Maricopa County is experiencing a devastating increase in suspected heat-related fatalities. As of this writing, the county’s heat surveillance dashboard lists 369 suspected heat-related deaths pending investigation. The official death toll today stands around 30 percent less than at this time last year. With 608 confirmed heat deaths as of 2023, Maricopa County is one of the most extreme environments for heat exposures in the country.
Besides Phoenix, Maricopa County includes much of the region’s first ring suburbs and independent cities, like Scottsdale, Tempe, and Mesa. This lethal combination of extreme heat and built environment density fuels the growing public health crisis as more people become susceptible to dangerous health outcomes.
Dr. Nick Staab, a public health expert, commented on the ongoing situation:
“With this many cases still under investigation and it only being mid-August, there’s a lot that could still happen.”
Though the number of heat-related deaths is shocking, a deeper dive into the data tells a more nuanced story. As a comparison, in 2014, Maricopa County only experienced 61 heat-related deaths, a stark difference relative to the growing heat-related deaths found in recent years. The heat exposure was definitively listed as the cause of death in 35 of those deaths in 2025 by the medical examiner’s office. Of these, 17 deaths were directly attributed to extreme temperatures, with heat contributing to an additional 18 fatalities.
Perhaps the most alarming aspect of this trend is the demographic impact of these fatalities. In addition, unhoused people make up nearly 40% of the county’s heat-related deaths. Substance misuse has come to play a major role, accounting for two-thirds of the extreme heat-related deaths. The intersection of homelessness and substance abuse sheds light on a concerning cycle. We need clear, coordinated plans to address the threats of extreme heat.
Stacey Champion, an advocate for public health reform, highlighted the urgent need for better tracking and transparency regarding heat-related deaths:
“People are dying awful, preventable deaths that are not being accounted for in the official figures. We need more consistency and transparency if we’re going to wrap solutions around this public health crisis.”
Despite these alarming figures, authorities have noted that this year’s official death count is lower than last year’s figures at this time. By year-end 2022, Maricopa County had recorded 645 heat-related deaths and counting. The overall drop is an encouraging sign of progress, likely stemming from increased public awareness and emergency response systems, but the real story is one of danger.
With August still rolling along and plenty of warm days to come, the threat of warning from further deaths still exists. Public health officials are encouraging them to strike now. Their goal is to prevent vulnerable communities from facing the long-term effects of extreme heat.