Today is the last day to register to vote in 18 states

(RNN) - The elections Nov. 6 are expected to see among the highest ever turnouts for a midterm cycle, but people in many states will miss out on participating if they aren't registered by Tuesday.

Registration ends completely or in part for the following states: Arizona, Arkansas, Florida, Georgia, Hawaii, Illinois, Indiana, Kentucky, Louisiana, Michigan, Nevada (by mail), New Mexico, Ohio, Pennsylvania, Tennessee, Texas, Utah (by mail).

Also, Mississippi’s last day to register by mail is Tuesday; in-person registration ended Monday. Missouri’s deadline for all registration is Wednesday.

Each state has its own rules on dates and requirements. Some deadlines have already passed, in Alaska and Rhode Island. Montana, for instance, ended in-person but mail registration is through Wednesday.

To find out more, go to your state’s secretary of state website or Vote.gov. The U.S. government’s official site also gives information on polling places, early and absentee voting, voter ID requirements in some states, and who’s running for office.