Grad Nites. New format this year so things will be different in some ways.
Grad Nites for from the 2nd week of May to the 3rd week of June and are on Wednesday- Friday night. The Party is 11pm to 3am in DCA. Grads get park hoppers to use during the day. They also got 2 FPs which may not be continuing this year.
If you go early in the season(May) they aren't too bad. Kids trickle in through the day and show up in mass after 5 PM. Evening is busy. May is generally a slow month so when the parks stay open later than 8, those grads are giving you bonus hours since the host park stays open later and you can stay until the party starts.
If you go late, post Memorial Day and especially into June, the Grads have graduated, school out. More show up early, particularily late morning. Also being summer for other the parks are busy in general. For most part the teens are noticeable but very mixed in to the normal big crowds.
Do a couple a few things. See WoC it requires a FP, so teens just can't squeeze in. Ride slow rides, it's a bummer but the teens are going on fast E tickets. Snow White won't have a line. Use FP for the big rides, Space and RSR will have crazy long lines as the Grads gravitate toward the thrills. Have a slow dinner, they don't have money and won't all be spending time sitting down to eat. Arrive early, the kids often meet at 8am at their school, you can be in the park for an hours or two before their buses start to arrive.
Be Cool Stay in School!
Next year I'm trying for a summer internship at Stark Industries.