SAN DIEGO (FOX 5/KUSI) — Monday is the deadline for voters in San Diego County's first supervisorial district to register for the upcoming special election. The race will decide former Board of Supervisors Chair Nora Vargas' successor in the South County seat. Vargas had abruptly resigned from the office shortly after residents in the district re-elected her for a second term back in November. Whoever wins in the special election will serve the remainder of the current term, which runs through January 2029. As the race is for a district-level seat, only residents in the first supervisorial district who have registered to vote before Monday's deadline will be able to cast a ballot by mail between now and the final day of voting on April 8. MORE: Board of Supervisors District 1 special election After the registration deadline, District 1 residents who are not signed up to vote but want to participate will need to head to a vote center to conditionally register and vote provisionally. Above: FOX 5/KUSI video on how conditional registration works in California. As of Monday, the only in-person option available to District 1 voters to participate in the election is to head to the county Registrar of Voters' office in Kearny Mesa. The first vote centers in the district are set to open on Saturday, March 29, with thirteen additional polling places opening on election day to accept ballots. The county Registrar of Voters encourages anyone who thinks they may be eligible to vote in the special election to look up what district they live in and double-check their voter registration status prior to 5 p.m. on Monday. Seven candidates are vying for the role: Imperial Beach Mayor Paloma Aguirre, Chula Vista Deputy Mayor Carolina Chavez, affordable energy consultant Elizabeth Efird, former Imperial County Board of Supervisors Chair Louis Fuentes, Chula Vista Mayor John McCann, San Diego City Councilmember Vivian Moreno, and long-time South County resident, Lincoln Pickard. As the contest is a special election, should one candidate garner more than 50% of the vote, they would win the race outright. If no candidate meets that threshold, the election will move to a runoff between the top two vote-getters in July. ...read more read less