Walnut Creek, CA is currently using one area code which is area code 925. Area code 925 was created from a split of area code 510 and put into service on March 14, 1998.
In addition to Walnut Creek, CA area code 925 serves portions of the East Bay region in Almeda and Contra Costa counties, including the larger cities and communities of Antioch, Bay Point, Brentwood, Concord, Danville, Dublin, Lafayette, Livermore, Martinez, Oakley, Pittsburg, Pleasant Hill, Pleasanton, San Ramon, and Walnut Creek in addition to many smaller communities within the service area.
Walnut Creek, CA is located in Contra Costa County and observes the Pacific Time Zone. View our Times by Area Code tool.