How do you find the zip code for a California town?

Use the ZIP Code locator provided by the US Postal Service. It is updated weekly, unlike other sites which are updated monthly at best. The direct URL for the ZIP Code Locator is:

http://zip4.usps.com/zip4/welcome.jsp

Some ZIP Codes, such as for small towns or suburbs, can be determined only from the town name. Others, such as for cities such as Los Angeles, will require a specific address to determine the correct ZIP Code. The USPS lookup allows either method.