California’s Secretary of State Alex Padilla is forecasting a large surge in the number of voters for the June 7 presidential primary.

Last week, he wrote to both Gov. Jerry Brown and county officials urging them to prepare for an unexpectedly large turnout. Padilla’s warning is based on the significant increase in the number of online voter registrations that have occurred and demand for registration cards.

“For example, in just the past three months, more than 600,000 California citizens have used our online voter registration site to register to voter, or update their registration,” Padilla said in his letter to Brown.

According to the Riverside County Registrar of Voter’s Office, the county registration has increased by 20,000 voters since January. There are now 865,000 registered voters in Riverside County and the 3rd District continues to be the largest with nearly 185,000 registered voters.

As of Jan. 5, the last reporting date for statewide registration, registered voters were 17.3 million compared to 17 million four years before and only 15.5 million in 2008.

“Given the increase in public interest in the upcoming presidential primary election and the rise in the number of online voter registration applications, it is anticipated that voter turnout in the June 7, 2016, presidential primary election could significantly increase as a result.

“Therefore, the Secretary of State’s office urges that you plan accordingly to ensure your county has an ample number of ballots, including any required multilingual ballots and other voting materials, available at your office and at the polls on election day,” Padilla said in his letter to state county election officials, urging them to prepare for the upcoming elections.

Riverside County Registrar of Voters Rebecca Spencer confirmed that her office had already initiated efforts for a large turnout.

“We are seeing an increase in voter registration cards and are expecting a higher turnout,” she said in an email to the Town Crier. “We are hiring extra temporary staff to keep up with the demand of resources for the June election … We have planned for a higher turnout in our current budget and will monitor our current budget closely and advise the Board of Supervisors accordingly.”

The Registrar’s Office is encouraging voters to vote by mail and return their ballots early to take some of the pressure off the polling places and allow for a large number of votes to be released in the first election results update shortly after 8 p.m. on election night.

Voters may register online at The last day to register for the June 7 primary is May 23. Vote-by-mail applications can be requested as late as May 31.