The latest figures suggest more than nine million people have voted so far, and although that is just a fraction of the 129 million who took part in the 2012 election, the data does give us some nuggets of insight.
Here's what we know so far, courtesy of our North America reporter Anthony Zurcher:
Because many states disclose the party affiliation of those who have voted, we know that Democrats and Republicans are running neck-and-neck in Florida - a good sign for Hillary Clinton, given that Republicans in the state usually early vote in larger numbers.
In Colorado and Nevada, Democrats are significantly outperforming past results at this point - more good news for the former secretary of state.
But the opposite is true in Iowa - a state Mr Trump desperately needs to win. Indications of lower turnout in Ohio's big cities could also be good news for the Republican.
Of course, this information tells us nothing about how those not affiliated to the major parties are voting - or how many Americans may be crossing party lines in this most unconventional election.
FiveThirtyEight: Americans love early voting, and it might help Clinton
One reason the Democrats may be doing slightly better in early voting is down to their ground game - knocking on doors, speaking to voters on the phone and handing out campaign materials (signs, stickers, etc) so they can show their support.
Critics say Donald Trump's campaign has failed to understand the importance of this and comments on Monday by a Republican official in a swing county in Nevada back that up.
Roger Edwards, chairman of the Washoe County Republican Party, told NBC News that he was desperate for more resources, but couldn't get the Trump campaign to send him any despite calling them every day and being in a swing state.
"I need 2,000 yard signs. I need 10,000 bumper stickers. And I don't even get a call back," he told NBC's Chris Jansing.
Who will win? Play our game to make your call
There was no shortage of signs at Donald Trump's rally in Florida on Monday, and they were the hot topic on Twitter. A few eagle-eyed viewers noticed one reading "Blacks for Trump" that was being held aloft by a white woman. A man dressed as a doctor directly behind her was also the focus of some online debate.
Mr Trump was campaigning in Florida on Monday and Tuesday this week, and it appears to have paid off - a new poll by Bloomberg has the Republican leading his rival by 45% to 43%. The RealClearPolitics polling average still has Mrs Clinton ahead, but only by 1.6%.
Meanwhile, Colin Powell, the Republican former secretary of state, is reportedly planning to vote for Hillary Clinton. He has criticised Donald Trump in recent months but it's the first time he's said he will back the Democratic nominee.
Another loss for Mr Trump is his namesake, Dr Donald Trump, an oncologist in Virginia, who told CNN on Monday that he disliked the Republican's "theatrical persona" and would vote for Mrs Clinton. That's got to hurt.
On the upside, the businessman looks like he can count on the support of his employees at the Doral Golf Club in Miami. Mr Trump held an event there on Monday, where he encouraged his staff to come up on stage and "say a few words about working for Trump". Take a look below:
$29.3 million
The amount being spent by the Clinton campaign and Priorities USA Action, the super PAC backing her, on TV ads in 15 battleground states this week, according to ad buyers. The Trump campaign and various groups that back him are reported to be spending $15.8 million in 12 battleground states.
In a surprise move for a presidential candidate, Donald Trump is taking time out of campaigning to open his new luxury hotel in Washington DC, before later heading to North Carolina to hold a rally at the Kinston Jet Center. Mike Pence, meanwhile, is holding rallies in Nevada, Utah and Colorado.
Hillary Clinton is in Florida, holding events in Palm Beach and Tampa, while her running-mate Tim Kaine is campaigning in Pennsylvania. Her army of surrogates is out on the road again, with Bill Clinton in North Carolina and her daughter Chelsea in Ohio.
Khizr Khan, the father of a Muslim-American soldier killed in Iraq, is also campaigning for Hillary Clinton in Norfolk, Virginia.
Who is ahead in the polls?
50%
Hillary Clinton
44%
Donald Trump
Last updated October 25, 2016
There are just 13 days to go until election day, but millions of people across the US are already casting their ballots in states that allow early voting.