rockscanfly:

The elections we refer to as Midterm Elections are held every four years, at the half-way point between presidential elections.

The big difference between a Presidential and a Midterm Election is, well, that you vote for the president in one and not the other. 

Midterm elections are held on a federal level because, by law, every House seat is open for re-election every two years, and every Senate seat is open every six years.

This is why in 2018 ALL 435 House seats will be up for re-election in 2018, but only 33 of the 100 Senate seats will be up. 

Also, midterm elections usually have state and local offices, issues, referendums, and propositions on the ballot. 36 of 50 state governors are up on the block in 2018. 

Please don’t underestimate how important your local issues are: whatever the federal government passes down, its usually up to the state how those laws will be enforced. See: like all of reproductive rights 

As for your questions regarding WHEN you can register:

Most states only require that you be 18 before the next election when you register. Check out the requirements for your state HERE.

So, for example, if you turn 18 ON OR BEFORE November 6th, 2018, you can probably register to vote now. 

Some states, like California, even give you the option of registering to vote on the same for that you use to register for a DL, a permit, or a state ID. 

HOWEVER: Not all states have the same rules regarding voting registration.

• Alaska: Be at least 18 years old or within 90 days of your 18th birthday

• Connecticut: Be at least 17 and turning 18 before Election Day

• District of Columbia: Be at least 17 years old, and turn 18 years old on or before the date of the next general election

• Georgia: At least 17 ½ years of age to register and 18 to vote.

• Iowa: 6 months before 18th birthday

• Louisiana: Must be 17 years old (16 years old if registering in person at the registrar of voters office or at the Louisiana Office of Motor Vehicles), but must be 18 years old to vote.

• Missouri: 17 ½ years of age to register, 18 years of age to vote

• Nebraska: 18 years of age on or before the first Tuesday after the first Monday in November of the current calendar year.

• New Jersey: 17 years of age to register, 18 years of age to vote

• New Mexico: 17 years of age to pre-register, 18 years of age to vote

• New York: 18 by end of calendar year that you register (note: you must be 18 years old by the date of the general, primary or other election in which you want to vote).

• West Virginia: Must be 17 years old and 18 before the next general election. 17 year olds may register and vote in primary elections if they turn 18 before the next general election.

• Wisconsin: Be at least 18 years of age on the day of the election to be eligible to vote. Persons who are otherwise eligible to vote may register to vote at 17 years of age if they will be 18 by the next election.

Hope this helps!