More than 2.5 million people had voted by mail in California’s June 5 primary election as of Monday night.
Data from the California Secretary of State’s Office shows about 13.5 percent of registered voters cast mail ballots.
That number will increase as residents vote in person on Election Day and as mail ballots continue to come in through Friday.
As long as a ballot is postmarked by June 5, it can arrive up to three days later and still be counted.
The counting process can take days and sometimes weeks for close races to determine a winner.
About 63 percent of voters received vote-by-mail ballots this election.
Polls in the state close at 8 p.m. Tuesday.
Turnout appears generally light throughout the state.