Climate Zone 9: LA Basin Inland
Hot, dry summers and mild winters in Los Angeles’ inland valleys.
Every Title 24 energy calculation uses the climate zone of the building’s physical location. In Zone 9, the climate is cooling-dominated, which shapes which building features have the most effect on compliance.
Typical project considerations
- Cooling efficiency, shading and glazing drive compliance.
- Roof and attic assemblies have a large effect.
General guidance only — requirements depend on building type, scope and the code edition in effect for your permit application.
Example communities
Pasadena · Burbank · Glendale
City guides: Los Angeles · Pasadena
Official references
Frequently asked questions
Where is California Climate Zone 9?
Climate Zone 9 (LA Basin Inland) covers areas such as San Fernando & San Gabriel valleys. Its representative weather city in CEC data is Burbank–Glendale. Boundaries don’t follow city limits, so confirm by address.
Does Climate Zone 9 change my Title 24 requirements?
Yes. All Energy Code calculations use the project’s climate zone, which affects prescriptive values such as insulation and window performance and how heating and cooling are weighted in performance modeling.
What report do I need?
Single-family projects use CF1R, low-rise multifamily uses LMCC and nonresidential projects use NRCC forms — regardless of climate zone.
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