Surviving East Bay Heat Waves: When 100°F Days Push Your AC to the Limit
June 1, 2026
When the National Weather Service issues an Excessive Heat Warning for Contra Costa and Alameda counties, East Bay residents know what's coming: multiple days of temperatures soaring past 100°F, with Brentwood, Antioch, and Oakley often hitting 105-110°F.
Why Heat Waves Are Different
Most AC systems are designed to cool indoor air about 20 degrees below outdoor temperature. On a typical 85°F day, maintaining 72°F inside is easy. But when it's 108°F outside, your system works dramatically harder—and may not keep up.
How Extreme Heat Stresses Your AC
Compressor Overload When outdoor temps exceed 100°F, compressors run longer with less rest time, accelerating wear and increasing failure risk.
Reduced Cooling Capacity Your system's efficiency rating is calculated at 95°F. At 105-110°F, efficiency drops significantly—your AC might run constantly yet struggle to maintain 78°F inside.
Electrical Strain Heat waves strain the entire grid. Brownouts and voltage fluctuations can damage AC components, particularly compressors and capacitors.
Warning Signs Your AC Is Struggling
- Running constantly but temperature keeps climbing
- Ice formation on refrigerant lines
- Warm air from vents
- Outdoor unit shutting off repeatedly
- Grinding, squealing, or clicking sounds
- Burning smell
If Your AC Fails During a Heat Wave
Immediately: - Close all blinds and curtains - Move to the lowest level of your home - Use fans and stay hydrated
Check before calling: - Thermostat batteries and settings - Air filter condition - Circuit breaker - Outdoor unit for visible ice
When to Call for Emergency Service
- Burning smell from your system
- Grinding or screeching sounds from outdoor unit
- Home reaching 85°F+ and system won't run
- Breaker trips repeatedly
We offer same-day emergency service during heat waves, with priority for elderly residents and homes with medical needs.
When the heat is on, we're here. Call (925) 778-1335.