What Temperature Should I Leave My AC When I'm Away in Arizona?
It's one of the most common questions we hear from homeowners before they leave for the summer — or head off on vacation: Do I just turn the AC off? Set it and forget it? Will my house be okay?
After 30 years working in construction and home services across the Arizona desert, Joe has seen what happens when this decision goes wrong. The answer isn't complicated — but it matters more than most people realize.
The short answer: never turn it off completely
In most climates, shutting off the AC while you're away makes sense. In Arizona, it's one of the costliest mistakes a homeowner can make.
When outdoor temperatures regularly exceed 110°F, an uncontrolled interior can reach 140–150°F. That's not just uncomfortable — it's destructive. Here's what we've seen happen inside homes left without climate control:
Wood floors, cabinetry, and furniture warping or cracking from the heat and dryness
Paint peeling off walls and ceilings from inside
Electronics and appliances degrading or failing under sustained extreme heat
Artwork, family photos, and keepsakes fading or becoming permanently damaged
Plumbing seals and pipe fittings breaking down — leading to leaks no one catches
AC units themselves becoming nesting spots for rodents, who chew wiring
The cost to cool your home down at a high setpoint all summer is far less than what you'll spend replacing flooring, cabinetry, or a damaged HVAC system.
"Turning your AC off entirely does more harm than good. You're better off keeping it running at a higher temperature than letting your home overheat."
So what's the right temperature?
The consensus among Arizona HVAC professionals is clear. Here's how to think about it based on how long you'll be gone:
80–85° - Short trip (1–2 weeks) — safe and energy-efficient
85° - Extended absence (1–6 months) — the sweet spot
Never off… In Arizona summer always keep it running
Setting your thermostat to 85°F keeps your home within a manageable temperature range, protects your belongings and systems, and avoids the brutal energy spike of cooling a home that has been baking in the desert heat for weeks.
If your home has specific items that require tighter climate control — a wine collection, original artwork, a home theater — consider dropping the setpoint to 80°F to be safe. Joe is happy to walk through your specific situation before you leave.
Book your free consultation here
What about the fan setting?
Set your fan to auto, not on. Leaving the fan running continuously wastes energy and puts unnecessary wear on the blower motor — particularly during monsoon season when humidity spikes and the system has to work harder.
Consider a smart thermostat before you go
If your home doesn't already have one, a smart thermostat is one of the best investments a Cave Creek homeowner can make before leaving for an extended period. It lets you monitor and adjust your home's temperature remotely from your phone — so if something doesn't look right, you can respond immediately without waiting for the next scheduled home watch visit.
Nest and Ecobee are both well-regarded options for Arizona homes. Many of our clients pair a smart thermostat with our home watch service — so they get both remote visibility and professional eyes on the property on a regular schedule.
But temperature alone isn't the whole story
Setting your AC to 85°F is necessary — but it's not sufficient. Here's the honest truth: even a well-set thermostat can't protect you from an AC unit that fails mid-July, a water line that slowly develops a leak, or a monsoon storm that damages your roof while you're 1,500 miles away.
That's exactly what Desert Peak Services is here for. We perform regular interior and exterior inspections while you're away — checking your HVAC system, plumbing, irrigation, pool equipment, and more — and send you a photo report after every visit so you always know the condition of your home.
We're not just looking for disasters. We're catching the small things before they become expensive ones.
Leaving soon? Let's walk through your home first.
With our free consultation, we’ll visit your property and walk you through our full pre-departure checklist before you leave your home alone.