1. Grow square melons
Watermelons aren't the only fruit that can be grown square. Tomatoes and cucumbers have also been grown square. The logic behind this is simple. The fruit's growth is restricted to a cute, bottle, or container that's placed around the fruit. You can even buy kits in hobby stores that come all ready to grow. BUT.. Think about how much fun it would be to do this on your own.
2. Magnet mania
Give the kids a bunch of magnets, metal objects (paper clips are great) and sting. Teach them about magnetism. You can even have races. Your metal piece on top of the table and your magnet below.
Here are some others: http://www.coolmagnetman.com/magindex.htm
3. Wildflower hunt
Go on a wild flower hunt, then try to identify them using the internet and books from the library. You can then create various activities using your flowers. These activities have been previously stated.
4. Grow a miniature garden
Find an empty wooden box, glass bottle, or plastic container, fill it with soil from the garden (ask Mom first) and plant flower or vegetable seeds. Watch them grow.
5. Grow a frog
If you live near a lake, pond, or stream, look for tadpoles and place them in a container. Take care of them and watch them turn into frogs.
6. Build a recycled aquarium
Find an old aquarium, clear plastic container, or large bottle, and look for materials to make an aquarium. The idea is to use 100% recycled materials. That means absolutely NO buying anything (except maybe the fish).
7. Make a rainbow
There are many fun ways to make a rainbow. The best looking rainbows can be made if you have a glass prism. They can be bought from a science supply store, hobby store, or hardware store. Alternatively, you can use everyday household items to make your rainbow. This is a good way to add a bit of learning into a fun experiment.
Here are some tips: http://www.wikihow.com/Make-a-Rainbow
8. Make your own bubbles
Bubbles are super fun. You can get them really cheap anywhere, but they're more fun if you make your own and blow them on a windy day. If you have a bubble blowing machine, make a million bubbles and see who can burst the most. You can try out these different bubble recipes. http://www.bubbles.org/solutions/
9. Magnifying hunt
Give the kids a magnifying glass each and let them loose around the yard. They'll learn a thing or two for sure.
10. Make your own frisbee
Make your own super duper frisbee and play them in the park or backyard.
Heres easy instructions: http://www.wikihow.com/Make-a-Frisbee
11. Make green slime
Make your own green slime in this fun science experiment.
http://www.youtube.com/watch?v=gIoKxmlMpJw&feature=related
12. God bird-watching
Record or take photos of the birds you see and find out their names on the internet.
13. Recycle Day
Go on a walkabout with your kids about the neighborhood and collect soda cans, old newspaper, and other recyclable materials that can be sold to recycling centers.
14. Go on an animal hunt
If you live near a green patch or near the woods, photograph or count how many types of animals you can spot.
15. Build an ant farm
Build an ant farm and watch how they scurry about doing their jobs. Teach your kids about how ants live and how each type of ant has its own responsibility. Try to identify the different types of ants in your ant farm.
http://www.essortment.com/instructions-build-ant-farm-58179.html
16. Catch fireflies in a bottle
Catch fireflies and watch them glow in a bottle! Here's an effective way to catch fireflies: http://www.firefly.org/how-to-catch-fireflies.html
17. Make a time capsule
Time capsules are a snap-shot of stuff. Make a time capsule containing personal items and stuff like newspaper clippings and photos.
http://www.ehow.com/how_6637_make-family-time.html
18. Go soda can hunting
Go for a walkabout or bike ride and collect soda cans. Send them to the recycling center. You might just earn a dollar or two for your hard work. A good way to find lots of soda cans is to go to places with lots of people traffic. If you're not into picking icky stuff, wear a pair of gloves or use a trash pick up tool.
This now completes my SUMMER ACTIVITIES section and I hope you all learned a thing or two. All of these ideas were from the following site: http://www.squidoo.com/kidssummeractivities