School's out until September. Most students (and teachers) are ready to take some time off and relax. If you are moving into your junior or senior year - don't do it!
This is the perfect time to get ready for the SAT or ACT. Your study will not compete with homework. Your SAT/ACT study will not compete with team practices or after school jobs.
Keeping the brain cells active this summer will reduce the shock and memory loss in September. Plus, you'll be ready to an early SAT/ACT exam in the fall before school really gets going. The biggest benefit: Studies have shown that students raise their scores every time they take the SAT/ACT. Give yourself the room to take the exam multiple times and send your best score to your schools of choice.