During a 105 degree stretch, an AC that runs nonstop and holds the house in the low 80s may be doing all it can. An AC that blows warm air, ices up or shuts off is failing. Keep people safe first, then sort out which one you have.
Updated October 29, 2026 · Sources listed at the end
Stockton Metropolitan Airport now averages 29.2 days a year at 100°F or more, up from 18.9 in 1991-2020. In 2024 it had 49, the most in the record. The hottest reading is 115°F, first on July 23, 2006. The longest run of 100 degree days was 14 in a row, ending August 2, 1980.
Heat waves are when the valley's usual night cooling fails. On July 23, 2006, the airport low was 82°F. When nights stay that warm, a system never gets its usual overnight catch-up.
JanFebMarAprMayJunJulAugSepOctNovDec
Every day of 2026 so far, colored by the afternoon high at Stockton Metropolitan Airport. 60 days reached 95°F and 19 reached 100°F through October 24, 2026.under 6060s, 70s75 to 8485 to 9495 to 99100 to 104105+NOAA NCEI daily summaries, station USW00023237.
Normal struggle or a real failure
Probably normal: the system runs all afternoon, the air at the vents is cold, and the house sits a few degrees above the setpoint until evening.
A real failure: warm air from the vents, ice on the copper lines, water around the indoor unit, a buzzing or humming outdoor unit with the fan not spinning, or a breaker that keeps tripping.
Most residential systems are designed to hold a certain temperature difference between inside and out on a design day, not to keep the house at 72 when it is 108 outside. If yours is cooling but losing ground, set the thermostat a little higher, close the blinds, and let it run. If it is failing, turn it off and call. The first ten minutes.
Keeping people safe
The CDC says people without air conditioning are at higher risk during extreme heat, and that older adults, young children and people with chronic conditions are the most vulnerable. The National Weather Service lists heat exhaustion signs as heavy sweating, cold and clammy skin, dizziness and nausea. Heat stroke, with a body temperature of 103°F or more and confusion, is a 911 call.
San Joaquin County's Office of Emergency Services opens cooling centers in libraries and community centers during heat advisories and posts the list on sjready.org. If the house can't be kept safe, go to one, or to a relative's place with working air conditioning, and deal with the repair from there.
Power outages
If the whole house is dark, check PG&E's or Lodi Electric's outage map. Ready.gov advises keeping refrigerator and freezer doors closed and using generators only outdoors, away from windows. When the power returns, give the AC a few minutes before turning it back on.
Questions Stockton homeowners ask
Why can't my AC keep up when it is over 100 degrees?
Most home systems are sized to hold a certain difference between indoor and outdoor temperature. On the hottest afternoons the house can drift above the setpoint even with a working system. If the vents blow warm air or the system ices up, that is a failure.
Where are cooling centers in San Joaquin County?
The county's Office of Emergency Services opens cooling centers at libraries and community centers during heat advisories and lists them on sjready.org.