Monsoon prep for your AC: storms, surges and dust
The monsoon brings the heat and the humidity together, then adds dust, lightning and power flickers. A little prep keeps the AC out of the storm’s way.
What to watch for: Short and practical: thermostat Off while the power is unstable, wait a few minutes, then restart. The surge protector he mentions is installed by a pro.
Why does this matter in Tucson?
The National Weather Service treats June 15 through September 30 as monsoon season in Arizona. The hazards it ties to that window include extreme heat, strong winds, dust storms, flash flooding, lightning and wildfire. Several of those land squarely on an outdoor AC unit.
Power flickers are the quiet risk. A compressor and fan that lose power and get it back a second later are restarting under strain. Turning the system off while a storm is overhead, then back on once power is steady, is free protection.
What you'll learn
- What to check before June 15, from the ground
- Why you set the thermostat to Off when the lights start flickering
- How to restart the AC after an outage
- What to ask a pro about surge protection
How do you do it, step by step?
- Before the season: walk around the outdoor unit and clear weeds, trash and anything that can blow into the fins.
- Tie down or put away patio furniture, trash bins and yard items near the unit.
- If you have a roof package unit or rooftop ductwork, look from the ground for missing panels or damage. Do not climb up during or right after a storm.
- Put a fresh filter in, and keep a spare on hand for after a dust storm.
- When lightning is close or the lights flicker, set the thermostat to Off and wait out the storm.
- After an outage, wait a few minutes once power is steady, then set the thermostat back to Cool. If the AC won’t start, check the breaker once.
- Ask the pro or a licensed electrician whether a surge protector for the AC or the whole panel makes sense for your home. That is an install job, not a DIY one.
When should you stop and call a pro?
- Floodwater reached the outdoor unit. Don’t run it until a pro has checked it.
- A roof panel is missing, or water is coming in around a rooftop unit or duct.
- The AC won’t restart after one breaker reset, or you smell burning after a lightning strike.
If a dust storm catches you on the road, ADOT's advice is Pull Aside, Stay Alive: pull fully off the road, turn your lights off and take your foot off the brake.
Read next
Sources and official pages
Rather have a pro handle it?
Climate Pros Tucson matches homeowners with licensed local HVAC pros across the Tucson area. You talk to us, then to the pro, and the pro quotes the job before any work starts.
What else can you check yourself?
Swamp cooler spring start-up and pad change
An evaporative cooler sat dry all winter. Fresh pads, a clean pan and clear water lines get it ready for the dry heat of spring.
Winterize a swamp cooler before the first freeze
Freezing nights are rare in the basin, but a cooler full of water and an open duct all winter cost you either way. Drain it, shut it off and seal it up.
Get ready for an AC or heat pump replacement quote
Twenty minutes of homework before the visit gets you quotes you can actually compare, and a contractor who sizes the system to your house.