Developing Story Note: This report covers new developments involving 2026 heat-related deaths in Maricopa County, Arizona. The figures are preliminary and come from Maricopa County Department of Public Health data as reported by KJZZ on Sept. 24, 2026. As of Sept. 27, they were the most recent publicly reported figures. Counts may change as the Office of the Medical Examiner completes its investigations.
Maricopa County has confirmed 230 heat-related deaths so far in 2026, a 60% increase from the number confirmed at the same point last year, according to county data reported by KJZZ. Another 567 deaths remain under investigation as possibly heat-related. Preliminary data also show that 34% of this year's heat deaths so far occurred indoors, up from about 24% over the previous three years.
The indoor shift moves much of the danger from streets and parks into homes. KJZZ reported that indoor heat deaths typically involve low-income households that cannot afford to run their air conditioning or fix it when it breaks. In the county's 2025 data, an air conditioning unit was present in 94% of indoor heat deaths, but it was not working in 72% of those cases. For families in the Phoenix area, a broken unit or an unpaid utility bill can become a serious health risk, especially for older relatives.
Indoor Deaths Put Home Cooling in the Spotlight
Officials caution against reading too much into early demographic patterns. Early data suggest people experiencing homelessness may account for a smaller share of this year's deaths than in previous years. In 2025, they accounted for 49%. "We'll have to wait until all the work is done, because we do sometimes see those kind of skewed numbers," said Dr. Jeff Johnston, Maricopa County's chief medical examiner.
Financial strain is part of the picture. Jessica Berg, chief program officer at St. Vincent de Paul, told KJZZ that many families are having to choose between food, rent, utilities, medical bills, and transportation. KJZZ also reported that nearly half a million Arizonans lost SNAP food benefits this year, while gas and utility prices rose.
Heat deaths in the county fall heavily on older adults, people with heart or lung disease, and people who use drugs or alcohol. In the county's 2025 heat-related deaths report, 55% of deaths involved substance use, and cardiopulmonary disease contributed to 47%. Ninety percent of indoor deaths that year were among people age 50 and older.
Family members can check daily on older relatives, make sure their air conditioning works, and ask utilities about bill assistance. Residents can call 2-1-1 for help finding cooling centers and utility assistance, and eligible residents can get transportation to heat relief sites. Most Heat Relief Network sites operate through Sept. 30.
According to the CDC's guide to heat-related illnesses, heat exhaustion can cause heavy sweating, weakness, dizziness, nausea, and headache. Confusion, loss of consciousness, seizures, hot skin, or a very high body temperature can signal heat stroke, a life-threatening emergency that requires calling 911.
A Reversal After Two Years of Decline
MedicalDaily previously reported that the medical examiner had confirmed 113 heat deaths as of Aug. 22, more than triple the 35 confirmed at that point in 2025. The confirmed count has since roughly doubled to 230. The gap with last year has narrowed to 60% because the 2025 count also climbed quickly over the same period, but 2026 remains well ahead.
The increase reverses recent progress. Heat deaths reached a record 645 in 2023, fell to 608 in 2024, and dropped to 430 in 2025, according to the county's final report, after a preliminary count of 427. "We were really happy to see that decrease, knowing that every single one of these deaths is preventable," said Kelli Donley Williams, deputy director of the Maricopa County Department of Public Health.
This year's heat started earlier and hit harder. Phoenix reached triple digits in mid-March, and the county confirmed nine heat deaths tied to that heat wave. This summer, Phoenix had 29 nights with lows of 90 degrees or higher, compared with an average of seven per year from 1991 to 2020. "It seems to be those overnight lows that aren't getting below 90, particularly on consecutive days, that seems to be riskiest," Johnston said.
An 18-day extreme heat warning ran from late July into August. During one week in August, Johnston's office investigated about 230 cases, roughly double its typical weekly average of 120.
The 567 deaths under investigation are a ceiling, not a forecast. The county's heat surveillance page says it is unlikely that all of them will be confirmed as heat-related, and investigations usually take two to three months. Johnston expects the 2023 record of 645 to stand, but said the final 2026 total could easily be the second- or third-highest on record. The county's final report on 2026 deaths is expected next spring.
Funding Cliff Looms for Next Summer's Cooling Network
The county's public health department spent about $3 million on heat relief this year, and about $2.8 million of that came from the federal American Rescue Plan Act (ARPA), a county spokesperson told KJZZ. That pandemic-era funding expires at the end of 2026. The county's 2026 heat plan had already identified this season as the final year of ARPA funding for expanded heat relief. KJZZ also reported that 211 Arizona, which helps connect callers to heat relief resources, is set to run out of funding for live operators in early 2027.
"Next year is going to be very different resource-wise," Donley Williams said. David Hondula, director of Phoenix's Office of Heat Response and Mitigation, said the higher numbers show the problem "continues to need and demand a large-scale, coordinated, regional effort."
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Key Questions Answered
How many heat deaths has Maricopa County confirmed in 2026? As of county data reported Sept. 24, 230 deaths were confirmed, 60% more than at the same point in 2025, with 567 more under investigation.
Will all 567 pending cases be counted? Unlikely. The county describes that number as the maximum possible, and investigations usually take two to three months.
Why do indoor heat deaths matter? About 34% of this year's heat deaths so far occurred indoors, up from about 24% in recent years. In 2025, most indoor deaths happened where an air conditioner was present but not working.
Is 2026 a record year? The chief medical examiner expects the 2023 record of 645 to stand, but said 2026 could rank second or third.
Who is most at risk? Older adults, people with heart or lung disease, people who use drugs or alcohol, and people in homes without working air conditioning.
Where can residents get help? Call 2-1-1 for help finding cooling centers, utility assistance, and transportation. Call 911 for confusion, fainting, or other signs of heat stroke.
Published by Medicaldaily.com
