The same way as I do during the spring, fall, and winter.
During the summer, our trampoline gets utilized quite a bit, as well as the bikes, and scooters. The hot afternoons are filled with Lego creations, iPad apps, and good old fashioned books. When it isn't so hot, hiking fills up a couple of hours of afternoon time with nature, rock climbing, and imaginary forest adventures.
Beyond that, every day household chores help them develop a work ethic, and learn responsibility.