Summer is the best time to lose weight - healthy fruits and vegetables, awesome weather to play outside!
If you're hungry and need a snack between means, try to eat more fruits and vegetables. Drink lots of fluids. It'll help cool you down on a hot summer day, plus most of the time when you feel hungry you're actually thirsty.
Spend time outdoors: biking, jogging, hiking, rock climbing, swimming, volleyball, tennis, dancing, etc. Try a new sport each week. Don't like it then switch to something else the next week. Give yourself a chance to try it. Want something less intense? Join a tai chi class. It's low impact and you'll be surprised it's not as easy as it looks. Same with yoga and core strengthening exercises. All these are designed to help you stretch and strength your muscles which will make them look toned.
Good luck and have fun!