JA2.1    Weather Data - General

All energy calculations used for compliance with the Standards must use the Commission's sixteen (16) official hourly weather files or modifications of these files adapted for the design day conditions in Table 2-3. The modified weather files make the HVAC sizing and energy calculations more realistic for energy compliance simulations. These files are available in electronic form from the Commission in CSV (Comma Delimited File) format, TMY2 (Typical Meteorological Year) dataset and EPW (EnergyPlus) format.

Each weather file contains data on a variety of ambient conditions such as:

(a)  Dry bulb temperature

(b)  Wet bulb temperature

(c)  Wind speed and direction

(d)  Direct solar radiation

(e)  Diffuse radiation

Table 2-1 –California Standard Climate Zone Summary
Note: The alternative weather files modified for local design conditions
use the specific latitude, longitude and elevation of the selected city.

JA2.1.1 Counties and Cities with Climate Zone Designations

The climate zone applicable to a building project is determined based on its physical location as it relates to the determinations of climate regions found in the Commission publication California Climate Zone Descriptions, which contains detailed survey definitions of the 16 climate zones.

Where a ZIP code contains more than one climate region, local jurisdictions may, at their discretion, designate a single climate zone within the ZIP code as applying to the entire ZIP code. The Executive Director will publish a list of California cities, ZIP codes, and counties with climate zone designations for each ZIP code as an aid to local officials. New ZIP codes listing approved by the Executive Director will be published as addenda to this list, and may consist of additional rows or columns to existing tables.

Link to Climate Zones by Zip Code