Fill a large, wide-mouthed jar with two inches of very hot water, cover the jar opening with a small glass plate and wait a few moments for the bottom of the plate to heat up. Add 3 or 4 ice cubes to the plate. After a few moments, condensation will begin and water droplets will begin to fall. Explain to the children that rain is caused by warm, moist air meeting colder air as it rises in the atmosphere. Water vapors form into clouds, and then the rain falls to the earth.
Give each child a small plastic cup filled halfway with potting soil and a seed that will sprout and grow quickly, such as corn or beans. Help the children plant the seed and explain that plants need rain and sunshine to grow and live. Place the plants in a window sill, allow the children to water their plants every day and watch the plants grow. Show the children how important rain is to plants and how they use water. Place a celery stalk into water tinted with food coloring and wait a few days; the celery will turn the color of the water. Split the stem of a carnation in half and place each half of the stem in a container of different-colored water. After a few days your flower will be two different colors.
Explain to the children that the sun provides light and warmth to the earth. Cut a 6-inch circle out of yellow construction paper for each child. Trace each child's hand six times on orange and yellow construction paper and cut them out. Have each child draw a face on the circle, then help them glue the bottom of the paper hands to the back of the circle so that the fingers flare outward, forming the sun's rays.
Give each child a piece of thin cardboard and a dark-colored piece of construction paper, such as blue, green, purple, red or black. Have each child draw shapes on the cardboard and cut them out using safety scissors; if the cardboard is too thick, help with the cutting. Use putty or removable tape to attach the cardboard shapes to the construction paper, then place the project in the sun. Leave the projects outside for a few hours until the sun fades the paper; the areas where the cardboard is attached will remain a dark color. Remove the cardboard and allow the children to decorate their sunshine paintings with markers, chalk, crayons or paints.