It’s primary election day. Here’s what you need to know.

Nearly 20% of residents across Salt Lake County have already cast their ballots in this year’s primary election, which includes a handful of hot mayoral contests.

But it’s not too late for voters who haven’t mailed in their ballots to weigh in on which candidates they want to see move forward to November’s general election — and “every vote” in these races will count “with this small of turnout,” said Salt Lake County Clerk Sherrie Swensen.

She and other county clerks across the Wasatch Front have raised concerns about low voter turnout so far, which is expected in an offseason election to be between 25% and 30% overall.

There are 22 voting centers throughout Salt Lake County, which are open from 7 a.m. to 8 p.m. on Tuesday. Voters can go to any one of them to drop off their ballots or cast their votes. Same-day voter registration is available at each location to those with photo ID (also required to vote in person) and proof of residency.

Voters can also skip the lines and turn in their completed ballots at any one of 20 drop box locations throughout the county before 8 p.m. on Tuesday.

The race to lead Salt Lake City is one of the more crowded and most watched across the county in this election season, with eight candidates facing off in an expensive race to replace Mayor Jackie Biskupski, who is not running for reelection. Contenders in that election include former state Sen. Jim Dabakis, current Sen. Luz Escamilla, Salt Lake City Councilwoman Erin Mendenhall and former Councilman Stan Penfold.

Businessman David Ibarra and former Southern Utah Wilderness Association attorney David Garbett are also running, along with retired electrical engineer Rainer Huck and freelance journalist Richard Goldberger.

Voter turnout in Salt Lake City was slightly higher than the overall average as of Monday afternoon, at 25.86% in Salt Lake City with about 24,584 ballots returned. Swensen said she expected that race to have between 40% and 50% turnout overall.

West Jordan and Brighton also have mayoral primaries this year.

Alta and South Jordan, along with Millcreek, are the only cities in the county that will not require primary elections. Voters who didn’t receive a ballot can check whether they have a primary at vote.utah.gov or by emailing got-vote@slco.org.