Weather - water cycle liter soda bottle cut in half. Put about an inch and a half of warm water (w blue food coloring) in the bottom. Invert the top of the bottle with the lid on and fill with ice. Watch the water condensate and watch it "rain")
Science project: 2 clear containers, water, shaving cream, food coloring, and droppers. Slowly pour the food coloring on top of the shaving cream clouds and watch the "rain" come down when the clouds get saturated.
Science -- Weather: Fill the cup with water. Put shaving cream on top for a cloud. Explain that when clouds get really heavy with water, it rains! Then put blue food coloring on top of the cloud, and watch it rain. Air and Weather unit
I love easy experiments that make science cool! This rainbow colored celery science experiment is simple to set up and really makes transpiration come alive for kids. // Experiment by Coffee Cups and Crayons
Salt Volcano: Pour several inches of water into a jar. Add about of vegetable oil. Drop in food coloring and observe what happens. Shake salt on top of the oil/water/food coloring mixture. Pour or sprinkle more salt, as desired.
Growing bean plants in CD cases so all the parts can be seen. Have kids write about their finding and act out/ put together a dance describing the life cycle from seed to plant (Movement, writing, science)
Be a Spring Explorer: 5 Nature Activities for Kids
This place has some great science and history ideas for the third grade. These could be edited to work with a higher or lower grade. Third Grade Thinkers: Science: Earth Cycles Need to make sure its accurate to prevent misconceptions!