It typically takes weeks for counties to process and count all of the ballots. Elections officials have approximately one month (28 days for presidential electors and 30 days for all other contests) to complete their extensive tallying, auditing, 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, or up to three days after, Election Day (vote-by-mail ballots postmarked on or before Election Day and received by the county elections official no later than three days after the election are included in the canvass). 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 before the ballot can be counted.
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.
The Unprocessed Ballots Report (PDF) features unofficial county updates on the number of outstanding ballots that still need to be processed during the official canvass. This information is voluntarily reported by county elections officials and may not be complete.
State law requires county elections officials to report their final results to the Secretary of State for presidential electors by December 6, 2016, and for all other contests by December 9, 2016. The Secretary of State will certify the results for presidential electors to the Governor by December 10, 2016, and will certify the results of all state contests by December 16, 2016. For the most up-to-date vote counts before the statewide certified results are published, you may contact a county elections office directly.