During each election cycle, hundreds of thousands of ballots are not counted on Election Day. Elections officials have approximately one month to complete their extensive tallying and certification work (known as the official canvass). Most notably, voting by mail has increased significantly in recent years and many vote-by-mail ballots arrive on Election Day. In processing vote-by-mail ballots, elections officials must confirm each voter’s registration status, verify each voter’s signature on the vote-by-mail envelope, and ensure each person did not vote elsewhere in the same election.
Other ballots that are processed after Election Day include provisional ballots (processed similar to vote-by-mail ballots), and ballots that are damaged or cannot be machine-read and must be remade by elections officials.
State law requires county elections officials to report their final results to the Secretary of State by December 7. The Secretary of State then has until December 14 to certify the results of the election.
For the most up-to-date vote counts before the statewide certified results are published, contact a county elections office directly.
http://www.sos.ca.gov/elections/elections_d.htm