On a 106-degree morning in late July, the heat respite center inside First United Church of Christ in downtown Phoenix was crowded with people trying to escape the heat. Some had dogs with them. Some were sleeping on mats on the floor. Some were scrolling on phones.
Jonathan Nelson was sitting right in front of a big fan, trying to cool off.
“I've been coming every day because the heat is really, really bad,” said Nelson, who, like most visitors at the cooling center, is homeless.
Nelson said he’d been spending his days in the cooling center, but had been spending most nights this summer under a bridge. The pavement stays hot and air temperatures don’t drop much after the sun sets, Nelson said.
“I've been in the hospital because of the heat. I've been in kidney failure because of the heat. This heat this year is by far the worst year ever in Phoenix, Arizona, and I was born and raised here,” Nelson said. “It’s horrible.”
Data backs that up — 2026 is on track to be the hottest year on record in Phoenix. The number of heat-related deaths in metro Phoenix is likely to be close to a record high this year, too.
Maricopa County has confirmed 230 heat-related deaths so far in 2026 — a 60% increase compared to the number of deaths that had been confirmed at the same point last year. Another 567 deaths are still under investigation this year as potentially heat-related, according to county data.
Maricopa County had been making progress to reduce heat-related deaths
Maricopa County won’t release its final report on heat-related deaths in 2026 until next spring. If those numbers do show a significant increase in heat-related deaths this year, it would be a tragic reversal after two years of progress toward reducing these fatalities.
The year-over-year number of heat deaths in Maricopa County decreased slightly in 2024 for the first time in a decade. Then in 2025, heat deaths fell a full 30% from the previous year.
“We were really happy to see that decrease, knowing that every single one of these deaths is preventable,” said Kelli Donley Williams, Maricopa County Department of Public Health deputy director.
While it’s hard to pinpoint the causes behind the drops, officials say investments in resources like the cooling center at the First United Church of Christ helped. Donley Williams said public awareness of heat risk has increased and heat relief sites across the Valley have become more coordinated with each other, offering increased access to cooling at more hours of the day.
“[In 2024 and 2025] we continued to increase the messaging about the Heat Relief Network,” Donley Williams said. “It was a great win for us in public health.”
Similar heat relief resources have been available in 2026 — the Maricopa Association of Governments’ Heat Relief Network offered more than 200 sites this year for free water and indoor public cooling across the county. Most of the sites opened in May and will run through the end of September. The network represents millions of dollars of investments from Maricopa County, the city of Phoenix, and other municipalities and organizations.
Dangerous heat began earlier than ever in 2026
Donley Williams said it is too soon to understand why heat deaths have risen this year, in spite of ongoing efforts to address the problem. But extreme heat this year began earlier than ever before.
The National Weather Service ranked this June through August the second-hottest summer season ever for the Phoenix area, but spring in Phoenix was so unseasonably hot that 2026 will likely have the hottest year-round average temperature on the books in the Valley.
Phoenix temperatures reached the triple-digits for the first time this year in mid-March, shattering records.
Donley Williams notes most cooling centers across Maricopa County aren’t available until May.
“When you have a 100-degree day in March, it's very difficult to know what to do because we haven't mobilized yet,” Donley Williams said. “When we see those temperatures that early in the year, it's dangerous.”
Maricopa County has confirmed nine heat-related deaths related to the March heat wave — an unprecedented total for so early in the calendar year. Heat-related deaths are rare even in April or May. And from 2020 to 2025, Maricopa County data shows just one other heat-related death in the month of March.
This summer brought hotter nights and one particularly brutal heat wave
Maricopa County not only had an earlier start to the heat season this year. It also had several periods of intense, round-the-clock heat.
“It seems to be those overnight lows that aren't getting below 90, particularly on consecutive days, that seems to be riskiest,” said Dr. Jeff Johnston, Maricopa County Chief Medical Examiner.
Most of the heat records broken in Maricopa County this year have been at night. Climate scientists say summer nighttime lows are warming much faster than daytime highs because human-caused carbon pollution and urban development are trapping heat close to the earth, even after the sun sets.
Medical experts say high overnight heat becomes dangerous because people who lack access to air conditioning never get a chance to cool off.
From 1991 to 2020, Phoenix averaged seven nights per year with low temperatures in the 90s. This summer, more than four times as many — 29 nights — never dropped below 90.
Only two years, 2024 and 2023, had more lows in the 90s — those were also the top two years for heat-related deaths in metro Phoenix.
And many of the hottest nights this summer happened one after the other.
Maricopa County’s deadliest year on record was in 2023, when 645 people died as a direct or partial result of heat exposure. In July of that year, temperatures were above 110 during the day and above 90 at night for most of the month. The National Weather Service issued a 29-day extreme heat warning — Phoenix’s longest warning ever.
This summer, the National Weather Service issued its second-longest extreme heat warning ever, which lasted 18 days from the end of July into August.
“Aug. 1 hit us with a really intense surge,” Johnston said.
Johnston said in a typical week his office might investigate about 120 deaths. But during the July 2023 heat wave, more than twice as many cases — about 250 in a single week — came in.
The heat wave this August led to a similar spike — about 230 cases in a week.
Johnston said he expects the 645 heat-related deaths in Maricopa County in 2023 will remain the record, but said the final tally in 2026 could easily be the second- or third-highest.
Human-caused climate change is driving even longer and more intense heat seasons. Johnston doesn’t see the problem of heat-related deaths getting any easier in years to come.
“It's got to be a community-wide effort for us to continue to reduce mortality on these fronts, because it's just going to continue to get hotter,” Johnston said.
More heat deaths appear to have taken place indoors this year
Temperatures are not the only factor in heat-related deaths. Some people, especially those who spend long hours exposed to heat, are statistically much more vulnerable.
The annual number of heat-related deaths in Maricopa County skyrocketed between 2014 and 2023. During that same time period, the number of unsheltered people living on the streets of Maricopa County more than quadrupled, according to the annual Point-in-Time homelessness count.
The drop in heat-related deaths over the past two years occurred as the number of unsheltered homeless people across the region has begun to level off.
Early data shows people experiencing homelessness may account for a smaller share of this year’s heat-related deaths in Maricopa County compared to previous years.
At the same time, the preliminary numbers show the share of indoor heat-related deaths may be increasing. Over the last three years, about 24% of heat-related deaths in the county occurred indoors. This year’s data is showing 34% of heat deaths so far have been indoors.
Indoor heat-related