Take heart, everyone, the election is winding down. There are only a few more days until we can heave a sigh of relief — at least, until campaigning for 2020 begins in six months.

It hasn’t been a pretty election, and lots of ink has been spilled over the various tactics of the two sides. But that’s almost over, right? We’ve all made our well-researched decisions and we’re ready to head to the booths? Not quite. Up until the very end, our voting choices can be shaped by unconscious biases and things beyond anyone’s control.

The location of the voting booth matters

First, where you vote can affect what you vote for. Studies have shown that voting in a school makes you more likely to vote for education funding initiatives, while voting in churches can make you more likely to vote for conservative candidates and against gay marriage. There’s even been some research showing that people who voted while leaning slightly to the left (because of a missing wheel on a chair) were more likely to favor “left-wing” views than those in a chair leaning slightly the other way.

So, you’re in the booth. Turns out the order of the candidate’s name matters, too, meaning that the candidate whose name is first tends to get more votes. This is called the ballot order effect and several studies across elections seem to back it up. In fact, this may have changed the winner in up to 12 percent of primaries in California over two decades. Why do we do see this effect? The usual explanation is because we’re all primed to automatically pick the first answer that appears. (In general, though, the effect is much larger in local elections where people might not have read up on the candidates than in big national elections.)

Shark attacks have influenced elections

People tend to think that they’re voting based on everything they’ve read or heard or watched, but this isn’t always the case. Another area of research claims that voters tend to reject candidates when things aren’t going well — which makes sense, until you realize that they do this even when the candidate had absolutely nothing to do with whatever is wrong. Take the 2000 election between George W. Bush and Al Gore. By coincidence, the election happened during a period of both floods and droughts. Researchers Larry Bartels and Christopher Achen analyzed both weather patterns and voting patterns during that election and estimate that anger over weather made people turn against then-vice president Al Gore, perhaps subconsciously believing that he was to blame for their problems. It may even have been enough to sway the historically close election, they say.

And then there are the shark attacks. In the summer of 1916, New Jersey was plagued by Jaws-type shark attacks where people died. Woodrow Wilson was running for reelection and, of course, did not cause the shark attacks. Still, his vote was much, much lower in those Jersey comes town November. And even local college football games can have an effect: one study showed that a win 10 days before Election Day helped get more votes for the incumbent. (That said, a recent paper has contested this finding.)

Finally, even if we’re not in the middle of a drought and there aren’t sharks lurking, it’s worth paying attention to the weather on November 8th. Some studies have suggested that every extra inch of rain reduces voter turnout by 1 percent, at least in the US, Netherlands, and Spain. The flip also seems to be true — so let’s all hope for sunny weather come Election Day so that many people turn out and do their civic duty.

Update: This post has been updated to add that a recent paper has challenged the “shark attack” finding.