To me summer means freedom. The freedom to step outside and enjoy comfortable weather. To just take a walk without having to prepare any special clothing. To just go outside and sit down and enjoy the sun on you. To have a long period of daylight and not be constrained by the limited times of winter.
I love the sound of crickets at night. It's sooo relaxing! Also, with summer, comes an endless sea of piña coladas! Another thing that I love is not having any clue of what day it is... or caring for that matter!