Summer melt refers to the students who graduate high school planning on going to college in the fall...but don't make it. It's hard to count exactly how many people this includes--it depends on who you ask, and how you define "planning on going to college"--but most estimates for high school graduates who change their plans over the first summer are between 10% and 40%. That's a lot of melting students! The majority of students affected by summer melt are low-income and/or first-generation, but it happens to some extent across the board.
Most of the advice about solving summer melt, or at least making it smaller, is directed at adults like high school counselors and college enrollment offices. This makes sense, because one of the main factors of summer melt is not having enough support or encouragement. However, there are things any incoming college student--at any year, not just the first year--can do to stay cool (as in, not melt) over the summer.
If someone is nudging you, don't ignore them. The main tactic people use to prevent summer melt is simply to keep in contact. Some high school counselors send text reminders to their now-former students reminding them to keep up with preparations for college. Some colleges have teams of administrators, students, or alumni who try their best to stay in touch with incoming first-year students and make sure they're doing what needs to be done in order to enroll in the fall. Some family members are known to nag at their children. Whoever is reaching out to you, do not ignore them! If you're absolutely, 100% sure you have everything you need, have done everything you need to do, and will have zero questions or problems, then politely tell them so. But almost no one is ever absolutely, 100% sure of such things, so stay in touch with those people. They're doing what has been demonstrated as useful to getting you where you want to be--even if not every single message is exactly what you need to hear in exactly the right words or tone--so keep engaging with them.
If no one is nudging you, then you have to find somebody to be your go-to. It can be a parent, family member, someone at the college, a teacher or counselor from your high school...almost anyone you trust. It would be better if it's a person with college experience. It should not be somebody who has an interest in you not going to college, like a boss at your summer job or a friend who isn't going to college. As soon as possible, just tell them what you're looking for. Something like "I'm trying to go to college this fall, but I know that the process from now till then can be tricky. Can I count on you to give me reminders and help me answer questions?" Wherever you go in life, whatever you do, finding a mentor can be the difference between huge success and solitary failure. So go ahead and get practicing now.
Understand the specific problem and practice saying it aloud. This is by far the most difficult piece of advice here, so let me tell a story to help explain:
Many years ago, I had a student--a senior, just weeks away from graduation--get really angry at the school. He was visibly upset, and said things like "I hate this school! It's so overbearing and fascist!" Now, this was a small and quirky magnet school for gifted & talented students. It had its faults, but I'd never heard it called fascist before then. I asked him, a normally cheerful guy, what was so wrong with the school. He was angry that the school was requiring him to wear the graduation cap and gown to the graduation ceremony. He just wanted to wear nice clothes without the cap and gown, but the "fascist" school wouldn't let him participate without wearing them. I tried to explain that virtually every high school and university in the country, possibly the world, has special clothes for ceremonies. That the funny hats and robes of our tradition go back to medieval universities; that there was nothing particularly wrong with asking people participating in a ceremony to wear ceremonial clothes. "But they messed up my order and I don't have gown that fits!" Ah, that was the problem. The wrong-sized-gown problem was easily fixed, but he didn't know that it was easily fixed. And, frustrated at the technical problem he didn't know how to solve, he decided he'd go without and be angry at the school instead.
I suspect that a similar thing happens with a lot of summer melt students. A problem comes up that they don't know how to solve. Maybe it has to do with going to an orientation week in the middle of the summer, when you don't have the money and getting a week off work isn't easy. Maybe the financial aid isn't working the way it was supposed to. Maybe there are forms asking for information you don't have. And so students, not sure what to do, decide they're just not going to college.
To prevent this from happening, you need two things. First, you need that person you can trust to help you out. And next, you need to be able to say very specifically what the problem is. You have to be able to say "I'm supposed to go to an orientation, but I have no way of getting there and I don't have the week off. What can I do instead?" You have to be able to say "now that I'm getting a better understanding of the real cost, I don't think this financial aid package is really going to be enough. What can I do to make this work?" You have to be able to say "I don't understand this form, and I don't have all the information. Is there someone who can help?" There's going to be someone on the college campus who can help you, but you'll need to know what help it is you're asking for, and you need someone--probably and adult--to help you figure it all out. But understanding and being able to explain the problem is always the first step to getting it solved.
Make a back-up plan. "We'll see what happens" is not a back-up plan. If it looks like there may be difficulty in you getting to college this fall, make a "just in case" back-up plan. Use if/then statements, like "if I can't get more financial aid and make this affordable, I will enroll at the local community college instead." It's hard to predict exactly what the problem may be or what the back-up may be. But for whatever problem you do encounter, work up a back-up plan while you're also trying to find a solution to the problem. So don't give up on the college you're think you're going to, but also look for other ideas that don't involve never making it to college.