Even children in the primary grades can makes these wind socks with a little help. Give each child a piece of 6-by-18 inch construction paper to decorate with markers or crayons. Glue nine long crepe paper streamers along the bottom edge of the back of the construction paper. Bring the two sides of the paper together to make a tube and glue them. Then staple a 30-inch piece of string or yarn to the top of the tube to make a hanger for the wind sock. Hang the wind sock outside and use a compass to tell which direction the wind is coming from when it blows.
To make a rain gauge, simply place a clear glass jar outside in area where it will receive rain. Tape a plastic ruler to the inside of the jar, so it's standing straight up. After it rains, look at the ruler to see how much rain has fallen. Check soon after it stops raining or some of the rainwater might evaporate.
Kids can make a barometer to read air pressure and predict if rain is on the way. Tightly cover the top of a jar or coffee can with plastic wrap and hold it in place with a rubber band, making the can airtight. Tape a straw horizontally over the plastic wrap so about two-thirds is on the container. Tape an index card to the can or jar behind the straw and mark where the straw touches the card. Record the location of the straw each day to track the air pressure. High pressure will make the plastic cave in, causing the straw to point up and low pressure will make the plastic expand, pushing the straw down.
This thermometer won't give you an exact temperature, but it will let you know whether it's getting hotter or colder. Fill a clear, plastic, narrow-necked bottle about one-quarter full with equal parts water and rubbing alcohol. Add a few drops of red food coloring. Suspend a drinking straw in the bottle, so it reaches the liquid, but doesn't touch the bottom of the bottle. Place modeling clay around the neck of the bottle to hold the straw in place and seal the bottle. When the temperature rises, the liquid in the bottle will expand and go up the straw.