Can I still register to vote on Election Day? Which states allow same-day registration?

Election Day is on Tuesday, Nov. 4, and time is running out to ensure you're registered and ready to cast your ballot.

If you're prone to waiting until the last minute to ensure your registration is up-to-date and ready to go, you may be in luck. More than 20 U.S states allow same-day registration during early voting and on Election Day.

Voters in New York City, New Jersey, Virginia and California will cast ballots for a mayor, two governors and a redistricting measure - early tests of Democratic and Republican strategies ahead of next year's congressional midterm election.

Twenty-three states and Washington, D.C., allow same-day registration. Most allow same-day registration on Election Day, though some have stipulations such as applying only to presidential elections or being available only through early voting.

Two states, Alaska and Rhode Island, allow same-day registration only for voting in presidential and vice presidential elections.