Why does my TEP bill jump in summer?

Your AC runs far more in Tucson’s summer than at any other time of year, and some of that running lands in the most expensive window of your rate plan. Heat, warm nights, a hard-working system and your plan’s peak window all stack up. When the bill climbs faster than the weather explains, Climate Pros Tucson matches you with a licensed local pro to check the system.

How hot does Tucson get?

The 1991-2020 normals at Tucson International Airport show about 68 days a year with a high at or above 100F. In 2024 the airport hit 112 such days, a record, according to the National Weather Service. July’s normal low is 76.3F, so the house doesn’t cool off overnight and the AC keeps running.

The annual numbers tell the same story. Tucson’s airport averages 3,424 cooling degree days against 1,333 heating degree days, about 2.6 cooling degree days for every heating degree day. July alone counts 720.7 cooling degree days.

What is TEP’s peak window?

TEP’s Time-of-Use plan has an on-peak window from 3 to 7 p.m., Monday to Friday, May to September. From October to April it’s 6 to 9 a.m. and 6 to 9 p.m. on weekdays. TEP lists alternatives to Time-of-Use: Basic, Peak Demand and Demand TOU. Run your own bill against each plan, or read the best TEP rate plan for AC. Northwest Tucson and Marana customers may be on Trico Electric Cooperative instead, so check your utility first.

What can push the AC to use more power?

  • Dirty coils. Dust storms in the monsoon can coat the outdoor condenser. A coated coil makes the system run longer for the same cooling.
  • Clogged filter. Restricted airflow makes the system work harder.
  • Leaky ducts. ENERGY STAR says a typical forced-air house can lose about 20% to 30% of the air moving through its ducts. That’s a national typical, not a Tucson measurement, but ducts in a hot attic or on a roof deserve a look. See duct leak repair.
  • Low refrigerant or a failing part. The unit runs and runs without catching up.
  • Old equipment. An aging system can cost more to run than a newer one. Ask a pro to weigh repair or replace.

How can you bring the bill down?

Change the filter on schedule, keep the outdoor coil clear of debris, and ask a pro about a tune-up. As listed by TEP in October 2026, the Efficient Home Program shows up to $160 total for an AC tune-up through a participating contractor. Confirm with TEP. More ideas are in lowering your AC bill in a Tucson summer.

For service, see AC tune-up and HVAC maintenance. Start at the Tucson HVAC hub.

When to call us

If the bill spiked and the system seems to run nonstop, call (520) 353-2520 and we’ll match you with a licensed local pro.