Do your heat prep between March and May, before the first 100F day, because Tucson’s normal high reaches 91.8F in May and 101.2F in June. Climate Pros Tucson can match you with a licensed pro for anything below that you can’t do safely yourself.

Why does Tucson prep start early?

The airport averages about 68 days a year at or above 100F (1991-2020 normals). June is the hottest month by normal high, and July has the most cooling degree days. A system that has sat idle since October should be tested while repairs are easy to schedule, not on the first 105F afternoon.

What belongs on the checklist?

1. Test cooling for a full cycle

Set the thermostat well below room temperature and let the system run. Check that air from the registers feels cool and the outdoor fan runs.

2. Change the filter

Dust loads filters fast in the desert. Change it before the season and check it again mid-summer. Our filter guide for Tucson dust covers sizes and schedules.

3. Clear the outdoor unit

Cut back plants and clear leaves, gravel and debris from around the condenser. Leave space on every side so air can move through.

4. Check the drain

Pour water into the condensate drain access if your system has one and confirm it flows. A backed-up drain can shut a system off.

5. Look at rooftop units

If your home has a roof-mounted package unit, check that the access panels are in place and the area around it is clear. Stay off a hot flat roof and don’t climb up unless you have safe access. Leave panel and coil work to a pro.

6. Plan for dust storms

Dust storms occur during the monsoon, which runs June 15 through September 30. Dust can clog filters and coils, so check both after a storm.

7. Set your TEP schedule

TEP’s Time-of-Use plans have a summer on-peak window of 3 to 7 p.m., Monday to Friday, May through September. Pre-cooling the house before 3 p.m. helps if you’re on one of those plans.

8. Write a backup plan

Know where you would go if the system fails, and who in the home is most at risk. Our guide for what to do when the AC dies in the heat helps.

What needs a pro?

Coil cleaning, refrigerant checks, capacitor tests and electrical work. As listed by TEP in October 2026, the Efficient Home program offers up to $160 total for an AC tune-up through participating contractors ($80 for a refrigerant charge repair, $40 for indoor coil cleaning and $40 for outdoor coil cleaning). Confirm with TEP or the pro.

More on the pro side in our pre-summer AC tune-up checklist and maintenance schedule. See the HVAC maintenance service and the Tucson HVAC hub.

When to call us

If the test run shows weak cooling, ice or a tripped breaker, get a pro in before the heat arrives. Call (520) 353-2520 and we’ll match you with a licensed local pro.