The climate zones are based on energy use, temperature, weather and other factors. They are basically a geographic area that has similar climatic characteristics.   The Energy Commission originally developed weather data for each climate zone by using unmodified (but error-screened) data for a representative city and weather year (representative months from various years). The Energy Commission analyzed weather data from weather stations selected for (1) reliability of data, (2) currency of data, (3) proximity to population centers, and (4) non-duplication of stations within a climate zone.  

The representative city for each climate zone (CZ) is: 

CZ 1: Arcata  CZ 5: Santa Maria  CZ 9: Pasadena CZ13: Fresno
CZ 2: Santa Rosa CZ 6: Los Angeles CZ10: Riverside CZ14: China Lake
CZ 3: Oakland  CZ 7: San Diego CZ11: Red Bluff CZ15: El Centro
CZ 4: Sunnyvale  CZ 8: El Toro  CZ12: Sacramento CZ16: Mount Shasta

There are two sets of Climate Zone data included in VSAT, the original and a massaged set.  In the massage data, the dry bulb temp has been modified in an effort to give the file a better "average" across the entire zone. Because only dry bulb was adjusted, the humidity conditions are affected and therefore the massaged files are not preferred.

The following pages are a listing of the climate zones associated with several thousand specific California cities, towns and other locations. This information represents an abridged version of the Commission publication California Climate Zone Descriptions, which contains detailed survey definitions of the sixteen climate zones.

Cities beginning with letters A-I

Cities beginning with letters J-Q

Cities beginning with letters R-Z