KTVU - Polling places here in the Bay Area open at 7 a.m. Tuesday, and close at 8 p.m.
Election officials are predicting a heavy voter turnout, partly due to the hotly contested race between Democratic presidential candidates Hillary Clinton and Bernie Sanders.
Any of the 17.9 million people who registered ahead of the May 23 deadline can vote in Tuesday's California Primary.
While only Republicans can vote in the GOP Presidential contest, Democrats and those who decline to state their party affiliation can vote in the Democratic race.
"We're seeing 18% more voters here compared to 2008 and we've issued 18% more vote by mail ballots this election than in November 2015, said John Arntz, San Francisco Department of Elections.
The number of mail-in ballots are also exceeding projections.
To find information about your county registrar of voters, click on the web links tab. http://www.ktvu.com/web-links