When the sun beats down on Arizona backyards, parked cars, and desert scrub, the most vulnerable residents aren't always human. This year, animals of all kinds—from tethered dogs to rattlesnakes buried underground—are dying from extreme heat in numbers that are alarming wildlife experts and animal welfare groups across the state.
Pets caught in their own yards
In Maricopa County, the Arizona Humane Society has responded to seven heat-related pet deaths in just three weeks, all but a few of them dogs. That's more than triple the two heat deaths the organization saw during the same period last year.
"I think what's most troubling is the majority of these deaths have actually been from dogs that have been in their own backyards or they've been on a patio in a condo or an apartment," said Jennifer Armbruster, senior manager of public relations at the Arizona Humane Society.
The animals were left outside without access to adequate shade, water, or shelter as temperatures climbed into the triple digits. These weren't stray dogs roaming the streets—they were pets, stuck outside in their own homes.
Maricopa County health officials are also warning people never to leave children or pets in a parked vehicle, even for a short time. Heat kills quickly in a car, and Arizona's Good Samaritan Law allows people to rescue pets or children from hot cars using the least force necessary after calling 911.
Maricopa County confirmed its first heat-related death of 2026 in April—an older adult male—and is already investigating dozens of suspected heat deaths.
Even desert natives are struggling
The heat isn't just killing domestic animals. It's pushing Arizona's most resilient wildlife toward their limits.
In July 2023, after weeks of temperatures over 110°F, consulting wildlife biologist Mike Cardwell discovered something he'd never seen in more than 25 years of tracking rattlesnakes: two adult Western diamondbacks that stayed underground during the hottest stretch and never came back up. They had died in their own burrows.
"Those snakes stayed underground during the hottest stretch and never came back up," Cardwell said. "If it's happening to rattlesnakes, it's hard to imagine it's not happening to other species as well."
Rattlesnakes are ectothermic, meaning they depend on environmental temperatures to regulate their body heat. Their ideal range is 80–85°F. During extreme heat, they stay in burrows during the day and hunt at night. But when ground temperatures stay dangerously high for days, even underground refuge becomes lethal.
"When it stays hot for days on end, they just don't move. And if they don't move, they don't eat," said Elijah, a venom keeper at the Phoenix Herpetological Sanctuary. Some snakes are dying from starvation rather than direct heat exposure because extreme nighttime temperatures prevent them from hunting safely.
Saguaro cacti showing heat stress
Even saguaros—the iconic cacti found only in the Sonoran Desert—are showing signs of severe stress. Researchers at the Desert Botanical Garden report that saguaro mortality rates have jumped from 1–2% annually to nearly 7% in recent years, driven by extended heat waves and high nighttime temperatures that interfere with natural respiration.
Northern Arizona's unique heat challenge
While Phoenix and Tucson dominate the headlines, northern Arizona—from the Sedona red rocks to the high-elevation ponderosa forests of Coconino County—is facing its own heat crisis. The region has seen above-average temperatures and hot, dry conditions persisting into 2026, with above-normal fire potential expected to continue through the summer.
Arizona Game and Fish Department says unseasonably warm temperatures are increasing the risk of rattlesnake encounters statewide, including in northern Arizona. The department warns that 13 species of rattlesnakes call Arizona home, more than any other U.S. state.
In northern Arizona's higher elevations, black bear activity is ramping up as the weather heats. Bears are roaming the landscape looking for food and water, and encounters with people and pets are more common during this period.
Meanwhile, mule deer populations across Arizona have declined due to drought, and does require adequate water from December through August to produce fawns. Following a dry fall and relatively dry winter, biologists don't anticipate a strong fawning season throughout 2026.
Arizona Game and Fish has repeatedly told hunters and landowners that wildlife concentrate around surface water during hot, dry periods.
Wildlife rescues overwhelmed
Liberty Wildlife, a Phoenix-based rehabilitation center, takes in approximately 10,000 animals every year, with many arriving during summer months when temperatures soar. The center says most injuries are human-involved—animals caught in fishing line, hit by cars, or entangled in soccer nets—but heat-related illness is common.
"Most of them are human involved," said Laura Hacket, Educational Coordinator at Liberty Wildlife. "It has something to do with how we impacted their lives."
If you find wildlife in distress, Liberty Wildlife's hotline is available from 8:00 a.m. to 8:30 p.m. each day to guide you through what to do to help those animals.
The ecosystem tipping point
Biologists warn that losing even one species can disrupt an entire ecosystem. Snakes help control rodent populations, while saguaros provide food and shelter for birds, insects, and pollinators. The loss of either could set off a chain reaction throughout the desert food web.
What you can do:
For pet owners, the message is clear:
- Bring pets inside during extreme heat, or provide legal shelter with shade and water at all times
- Never leave pets in parked cars, even briefly
- If you see an animal left outside without water, shade, or food, call police or the Arizona Humane Society for help
- For wildlife concerns, Liberty Wildlife operates a hotline at 480-998-5550 from 8 a.m. to 8:30 p.m. daily
- Watch your step at home—rattlesnakes can easily blend in with surroundings
- Carry a flashlight at night, especially on warmer nights when rattlesnakes are most active
- If you see a rattlesnake on a trail, step back and let it move away.
Rattlesnakes are not aggressive—most bites occur when someone tries to
corner or capture a snake.
"Even the little guys play a big role in keeping everything around us in balance," Elijah said.