Climate ZonesCalifornia

California HVAC Climate Zones

California spans 4 IECC climate zones. Find your exact zone, design temperatures, and get free Manual J load calculations for any California location.

Find Your California Climate Zone

Climate Zones in California

Climate Zone 2B

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Hot - Dry

Design Temperatures

Winter
31°F
Summer
108°F
Wet Bulb
71°F

IECC 2021 Requirements

Wall:R-13
Roof:R-30
Floor:R-13
Window U:0.4

Load Characteristic

Cooling-Dominated
dry Climate

Climate Zone 3B

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Warm - Dry

Design Temperatures

Winter
35°F
Summer
99°F
Wet Bulb
68°F

IECC 2021 Requirements

Wall:R-20
Roof:R-30
Floor:R-19
Window U:0.32

Load Characteristic

Balanced Loads
dry Climate

Climate Zone 3C

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Warm - Marine

Design Temperatures

Winter
41°F
Summer
81°F
Wet Bulb
63°F

IECC 2021 Requirements

Wall:R-20
Roof:R-30
Floor:R-19
Window U:0.32

Load Characteristic

Balanced Loads
marine Climate

Climate Zone 4C

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Mixed - Marine

Design Temperatures

Winter
29°F
Summer
85°F
Wet Bulb
67°F

IECC 2021 Requirements

Wall:R-20
Roof:R-49
Floor:R-19
Window U:0.32

Load Characteristic

Balanced Loads
marine Climate

Recommended Equipment for California

Based on Climate Zone 2B (Hot - Dry), here are typical HVAC equipment specifications for California installations.

Heating Systems

Gas furnace
Heat pump
Electric resistance
Typical AFUE Rating
80-90%

Annual Fuel Utilization Efficiency for California furnaces

Cooling Systems

AC (14-16 SEER)
Evaporative cooling (swamp cooler)
Typical SEER Rating
14-16 SEER

Seasonal Energy Efficiency Ratio for California AC systems

Why Accurate Climate Data Matters in California

Accurate Sizing

California's climate zone data ensures proper equipment sizing. No more callbacks from oversized or undersized systems.

Code Compliance

California building departments require IECC-compliant Manual J calculations. Our tool uses official California climate data.

Energy Savings

Right-sized systems based on California climate data reduce energy costs for homeowners and improve your reputation.

Get Free Manual J Calculations for California

Upload your California blueprint and get a professional Manual J load calculation with official climate zone data. First report is FREE.

Zone 2B design temps
IECC 2021 compliant
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Climate Zones by City in California

Get detailed climate zone information for major cities

Need California HVAC permit forms and building department contacts?

View California Permit Directory