Short answer: California is divided into 16 building climate zones defined by the California Energy Commission (CEC). Every Title 24 project is assigned one zone based on its address or ZIP code, and that zone sets the energy budget and several prescriptive requirements the design must meet.
California is divided into 16 official climate zones by the California Energy Commission. Each zone has its own Title 24 energy budget reflecting local temperature, humidity, and solar conditions.
What California Climate Zones Are
The 16 climate zones are the framework the CEC uses to set energy budgets across the state's varied geography, from cool coastal areas and mild valleys to hot inland and desert regions and cold mountain areas. Your project's zone is assigned by its exact address, often by ZIP code. These zones are specific to the Energy Code. They are not the same as USDA planting zones or other climate maps.
California Title 24 climate zones — your project's zone is set by its address. For the official map, see the California Energy Commission's climate zone resources.
Find Your Climate Zone
Your climate zone is set by the project's ZIP code or street address, not by the city name alone. To look it up:
- Check the CEC's climate zone lookup. The California Energy Commission publishes a climate zone tool and ZIP code list you can search.
- Watch for border areas. If your ZIP code sits near a zone boundary, the exact address decides the zone.
- Let us confirm it. When you order a report, we confirm the climate zone from your plans and project address before modeling, so you do not need to look it up yourself.
The 16 Climate Zones and Example Cities
The table below lists each zone with example cities from our location pages. Large cities and counties can span more than one zone because of elevation, distance from the coast and local geography. Always confirm the zone for your specific address.
| Climate zone | Example cities |
|---|---|
| Zone 1 | Confirm by address |
| Zone 2 | Santa Rosa, Napa, Petaluma |
| Zone 3 | San Francisco, Oakland, Berkeley |
| Zone 4 | San Jose, Sunnyvale, Santa Clara |
| Zone 5 | Confirm by address |
| Zone 6 | Oxnard, Ventura, Santa Monica, Huntington Beach |
| Zone 7 | San Diego, Chula Vista, Oceanside |
| Zone 8 | Anaheim, Fullerton, much of Irvine and Santa Ana |
| Zone 9 | Much of Los Angeles, Pasadena, Glendale, Burbank |
| Zone 10 | Riverside, Ontario, Temecula, Escondido |
| Zone 11 | Roseville, Rocklin, Lincoln |
| Zone 12 | Sacramento, Stockton, Modesto |
| Zone 13 | Fresno, Bakersfield, Visalia |
| Zone 14 | Ridgecrest, Twentynine Palms, Yucca Valley |
| Zone 15 | Palm Springs, Indio, Banning |
| Zone 16 | Tehachapi and other mountain areas |
Browse by region on our Southern California and Northern California pages.
Why Climate Zones Matter for Title 24
Title 24 is a statewide code, but the energy budget your design must meet is calibrated to your climate zone. The same standards can therefore require different envelope, HVAC, window and solar choices depending on the zone. All of this is determined when your address is modeled in CEC-approved software. See Title 24 requirements for what the code covers and Title 24 calculations for how the modeling works.
The zone influences the balance between heating, cooling and solar gain in the energy model. Hotter zones tend to emphasize cooling, window SHGC and solar. Cooler and mountain zones emphasize insulation and heating performance. We handle this automatically based on your address. For a closer look, see how climate zones affect your Title 24 report.
Common Project Types Affected
ADUs, garage conversions, new homes, residential remodels and multifamily projects all follow Title 24, with the budget set by climate zone. Explore our ADU, residential and multifamily services. Title24Comply serves projects in all 16 California climate zones.
Frequently Asked Questions
How many climate zones does California have?
Sixteen, defined by the California Energy Commission for the Title 24 Energy Code.
How do I find my climate zone?
Search your ZIP code or address in the CEC's climate zone lookup. If you order a report from us, we confirm the zone from your project address.
Can one city be in more than one climate zone?
Yes. Large cities and counties can cross zone boundaries, so the exact address decides the zone, not the city name.
Does my climate zone change the price of a Title 24 report?
No. Title24Comply pricing is based on project type and size, not climate zone. See pricing.
