By the time your child is in Middle School, you may think their days of summer camps are waning. They're probably mature enough to stay on their own now more, and they may not be as interested in the themed camps that were more attractive to them when they were younger. But summer programs for Middle Schoolers, if you find the right one, meet some important needs that just don't pause themselves when school is not in session.
Middle Schoolers, while seemingly responsible, still benefit from having adults nearby. Remember that this is an age that often overestimates its own capacities, and having a thoughtful adult as a guide or resource can help students to plan differently for things they want to accomplish or more graciously back away from the activities they may be overwhelmed by. At the same time, coordinated activities in Middle School offer the chance for students to develop their social voices, introducing them to peers outside of school or their immediate neighborhood and giving them the chance to develop their social and communication skills.
Finding these activities takes a little time and discernment. You want activities that are structured to provide reliability, but allow for agency and voice from the students. Ideally, they should have a climate that allows children to unwind and slow their own pace, but still challenge them socially, physically or intellectually. And they should have some say in where they go. You can set parameters within which they can choose, but the expressed choice and voice of the Middle Schooler will go far toward a successful summer.
Finally, make sure you make time to talk with your Middle Schooler regularly. The pace of summer is a good time to set new routines as a family, to protect time at the dinner table or regular time in the evening for board games or other family projects, and to begin to shift your own communication with your Middle Schooler from the kind of oversight you provided earlier to the kind of mentoring tweens and early teens need most. Practice your listening skills, asking open ended questions and listening authentically to the answers. Give less criticism and more companionship. First dates, first jobs, first teen angst: it's all coming down the pike. Take the time now to establish or secure your child's confidence that home is a place in which they'll always be loved, always be accepted and always be listened to, Winter, Spring, Summer or Fall.