Climate Zone 1: North Coast
Cool, foggy and maritime year-round, with very low cooling demand and a long, mild heating season.
Every Title 24 energy calculation uses the climate zone of the building’s physical location. In Zone 1, the climate is heating-dominated, which shapes which building features have the most effect on compliance.
Typical project considerations
- Heating efficiency and envelope insulation drive results more than cooling.
- Moisture management and ventilation matter in a damp marine climate.
- Solar production is lower than inland zones, which affects PV sizing.
General guidance only — requirements depend on building type, scope and the code edition in effect for your permit application.
Example communities
Eureka · Arcata · Crescent City
Official references
Frequently asked questions
Where is California Climate Zone 1?
Climate Zone 1 (North Coast) covers areas such as Del Norte & Humboldt coast. Its representative weather city in CEC data is Arcata. Boundaries don’t follow city limits, so confirm by address.
Does Climate Zone 1 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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