Climate Zone 3: Central Coast / Bay Area
Very mild marine climate with small seasonal swings and frequent summer fog.
Every Title 24 energy calculation uses the climate zone of the building’s physical location. In Zone 3, the climate is mild / balanced, which shapes which building features have the most effect on compliance.
Typical project considerations
- Low cooling loads mean heating and water heating dominate energy use.
- Many older homes — alterations and additions are common.
- Local reach codes may add requirements; check the jurisdiction.
General guidance only — requirements depend on building type, scope and the code edition in effect for your permit application.
Example communities
San Francisco · Oakland · Monterey
City guides: San Francisco · Oakland
Official references
Frequently asked questions
Where is California Climate Zone 3?
Climate Zone 3 (Central Coast / Bay Area) covers areas such as San Francisco, Oakland, Monterey coast. Its representative weather city in CEC data is Oakland. Boundaries don’t follow city limits, so confirm by address.
Does Climate Zone 3 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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