Editor‘s note: It’s Election Day. Stay informed with OPB on the presidential race, key congressional battles and other local contests and ballot measures in Oregon and Southwest Washington at opb.org/elections.

Election Day is Tuesday, and if you’re one of the increasing number of Oregon voters who are waiting until the last minute to submit their ballots, you may have questions. Here’s what you need to know to safely and successfully get your vote counted.

When are ballots due?

Ballots must be submitted to designated drop boxes or county elections offices by 8 p.m. Tuesday. Not sure where the closest drop box is? There’s a tool for that.

Related: What you need to know about voting in Oregon and Southwest Washington

What about mailed ballots?

A 2021 change in Oregon law means that ballots are now accepted as long as they are postmarked by Election Day — even if they don’t make it to elections offices until later. Ballots with valid postmarks that are received within a week of an election will be counted.

But many elections officials warn that simply mailing a ballot doesn’t guarantee an immediate postmark. The Deschutes County clerk has been telling voters to use a drop box this close to Election Day, since Central Oregon mail is trucked over the Cascade Mountains to Portland to be postmarked.

“I just can’t imagine a scenario, at least for myself, where I as a voter would take that ballot and put it into a mail box, rather than putting it into a drop box,” Deschutes County Clerk Steve Dennison told OPB.

In Eastern Oregon, Baker County Clerk Stefanie Kirby tells voters who want to use the mail that they should get their ballot postmarked by hand at a post office at this point. “Of course they can always use any official drop site location if they do not want to mail,” Kirby said.

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Even in Portland, election managers warn that a mail box is not as safe as a drop box if voters are waiting until Election Day to turn in their ballot.

“The guaranteed way to ensure that you get that postmark is to walk it into a post office,” Multnomah County Election Director Tim Scott told OPB last week. “At that point I might suggest that ballot drop boxes are a better way to go.”

The upshot: It’s safest at this point to use a drop box.

Related: Listen to 'OPB Politics Now'

When will results be released?

Clerks in Oregon can begin processing and tabulating ballots when they’re received, meaning that a big chunk of results will be released shortly after 8 p.m. on election night.

But those results will form an incomplete picture. Oregonians are waiting longer these days to cast ballots, with a sizable chunk now coming on on Election Day.

“We got over a hundred thousand ballots back on Election Day in the primary this year,” Scott said. “I anticipate that we will see that again.”

Ballots received on Election Day are unlikely to be accounted for in the first batch of results in Multnomah County, and likely other counties as well, meaning that races that look close as of the first ballot results could shift considerably.

And since counties update their vote tallies on different schedules, the results will flow in unevenly in the days following the election.

Just as with the presidential race nationally, voters may not have clarity on the outcome of close Oregon races — for instance, the hard-fought battle for Oregon’s 5th Congressional District — for days.

In Multnomah County, Scott said the initial release of results on election night typically accounts for between 50% and 80% of total votes cast, while results as of the Thursday following an election reflect between 90% and 97% of votes.

How about city of Portland races?

Races to decide Portland’s next mayor and the 12 councilors on a newly reconstituted City Council are more complicated than most others.

The city is using ranked choice voting for the first time, and elections officials say that the increased complexity of generating reports in that system means they will be updating results less often than other races: just once a day at 6 p.m., following the initial Election Day drop.

Scott told OPB that the outcome of most city races should be known by Thursday evening.