Should you turn the AC off when you leave for the summer?

No. Leave it on, set warmer than you’d live with. Tucson’s summer is the hard season for an empty house. The normal low in July is 76.3F at the airport, about 68 days a year reach 100F or higher, and the monsoon (June 15 to September 30) brings humid air. A house with the AC off gets hot and damp inside for months.

Whether your Tucson-area home is in Green Valley, SaddleBrooke, Oro Valley or the city itself, plan the AC the way you plan the rest of the house. Climate Pros Tucson matches you with a licensed local pro for the pre-departure check.

What setting should you leave?

Pick a setpoint noticeably warmer than your normal one. That keeps the AC running enough to remove humidity but not to cool an empty house like an occupied one. Ask the pro what setpoint fits your system and house.

  • Leave the fan on Auto rather than On, so the coil can drain between cycles.
  • Check that the thermostat has fresh batteries if it uses them.
  • A smart thermostat lets you see the indoor temperature from a distance. See smart thermostat installation.

Why does humidity matter in an empty house?

Dew points at the airport jump into the high 50s in July and August. A closed, cool house in humid air is where musty smells and mold start. The AC is also your dehumidifier. If you have evaporative cooling, shut it down for the season and don’t leave it running unattended in the monsoon, because it doesn’t work well in humid air.

What can the drain line do while you’re gone?

Condensate has to go somewhere, and weeks without anyone home are how a clog goes unnoticed. A float switch may shut the AC down when the pan fills, leaving the house to heat up. See AC drain line clogged. Ask the pro to clear the line and check the switch before you go.

What if the power goes out?

Monsoon storms bring strong winds, lightning and dust. A power loss while you’re away can leave the house without cooling. A surge protector and a thermostat alert help. See AC not working after a power outage.

What goes on the before-you-leave checklist?

  • Replace the filter.
  • Clear the condensate line and test the float switch.
  • Clean the outdoor coil.
  • Test the system through a full cooling cycle.
  • Arrange a house watcher to check the indoor temperature, the thermostat and the drain.
  • Note the TEP time-of-use periods if you’re on that plan. Summer weekday peak runs 3 to 7 p.m. from May to September.

An AC tune-up before departure covers most of this. HVAC maintenance is the related service page. Also see pre-summer heat prep checklist. Area overview: Tucson HVAC hub.

Booking the check before you go

To have the AC checked before you head out, you need a licensed pro on site. Call (520) 353-2520 and we’ll match you with a licensed local pro.