The California climate zones range from Zone 1, which includes areas with the warmest temperatures, to Zone 16, which includes areas with the coolest temperatures. Each zone is characterized by a unique set of climate-related variables, such as temperature, humidity, and wind patterns.

The climate zone in which a building is located can have a significant impact on its energy use. For example, buildings in warmer climates may require more cooling, while buildings in cooler climates may require more heating. envelope insulation requirement will change based on climate zone, By taking into account these climate-related variables and tailoring energy use accordingly, buildings can be constructed to be more energy-efficient and cost-effective while also reducing their impact on the environment.

It’s important to note that cities may occasionally straddle two climate zones. In such cases, it’s essential to verify the exact building location and correct climate zone before any energy calculations are performed. Additionally, if a single building development is split by a climate zone boundary line, it must be designed to the requirements of the climate zone in which 50% or more of the dwelling units are contained.

An example of each time zone :

Zone 1: The northwest of California, including the city of Eureka, scotia, crescent city, and Fortuna.

Zone 2: The northern region, including the cities of Santa Rosa, Sonoma, Cloverdale, San Rafael, and Ukiah.

Zone 3: The coastal areas of northern California, including the cities of San Francisco, Carmel Valley, San Mateo, Newark, foster city, Monterey, Santa Cruz, Fremont, union city, Berkeley and Oakland.

Zone 4: The inland areas of central and northern California, including the city of Milpitas, Los Altos, Gillory, Hollister, San Jose, Stanford, and mountain view.

Zone 5: The coastal areas of central California, including the cities of San Luis Obispo and Santa Maria.

Zone 6: The coastal areas of southern California, including the cities of laguna beach, laguna hills, Marina del Ray, el Segundo, rancho palos verdes, Ventura, Newport Beach, costa mesa, Manhattan Beach, Huntington Beach, Santa ana, fountain valley, Los Angeles, long beach, Santa Monica and dana point.

Zone 7: Southern California including the city of San Diego, vista, imperial beach, Chula Vista, Oceanside, Coronado, and Carlsbad

Zone 8: Southern California, including the cities of Irvine, Tustin, Orange, Placentia, Norwalk, Stanton, Downey, culver city, cypress, Fullerton, Anaheim, Brea, Aliso Viejo, Yorba Linda, walnut park, Buena Park, bell and commerce.

Zone 9: The area of southern California, including the city of Beverly Hills, studio city, la Mirada, reseda, Covina, Ojai, Van Nuys, Pasadena, Calabasas, Burbank, whitter, west Hollywood, diamond bar, walnut, Pomona, Canoga park, Los Angeles county, Azusa, Chatsworth, Monrovia, Santa Clara, San Dimas, hacienda heights, arcadia, woodland hills, simi valley, Glendora, temple city, El monte, and Baldwin park.

Zone 10: The inland areas of southern California, including the cities of Corona, Eastvale, Norco, Loma Linda, Temecula, highland, Hemet, Fontana, Redlands, Perris, chino, chino hills, lake Elsinore, Riverside, and San Bernardino.

Zone 11: The inland areas of California, including the cities of the red bluff.  Williams , auburn, le grand, Tracy pumps, and Pittsburg.

Zone 12: The mountainous regions of central California, including the city of Livermore, Pleasanton , riverbank, Rio Linda, Stockton, Oakley, Oakdale and Concord.

Zone 13: The mountainous regions of northern California, including the city of Madera, orosi, and Maricopa.

Zone 14: The mountainous regions of southern California, including the city of Twentynine Palms, warner springs, Lancaster, Barstow, Palmdale, baker.

Zone 15: The desert areas of California, including the city of palm springs , palm desert , rancho mirage and Bannings.

Zone 16: The mountainous regions of California, including the city of canyon dam, elk valley, and Tahoe city.

  • In summary, Title 24 California climate zones are a critical component of energy efficiency standards for buildings in California. By taking into account climate-related variables and tailoring energy use accordingly, buildings can be constructed to be more energy-efficient and cost-effective while also reducing their impact on the environment. It’s essential to verify the correct climate zone for a building location and ensure compliance with energy efficiency standards for sustainable building practices.