Fill a clear vessel -- a fish tank or something similar -- with water, and let it rest overnight or until it reaches room temperature. Fill one plastic cup with pebbles, icy cold water and blue food coloring. Fill another plastic cup with pebbles, red food coloring and warm water. Add the cups to the tank of water and watch as the colored water seeps out of the cups and into the tank. The warm water represents warm air and it will have a tendency to rise. The cold water represents cool air and it will tend to stay low.
Children young and old appreciate sitting out on a warm day to watch for shapes and animals in the clouds. Begin with a lesson on the main types of clouds for kids to identify. For younger kids, plan a cloud craft using cotton balls and construction paper. Set out trays of paint in gray, white and blue. The kids can stretch and dip the cotton balls into cloud shapes and glue them to the construction paper.
Fill a clear bottle about a third of the way full with hot water. Place an ice cube across the bottle's opening, and move the bottle in front of a light source. When the cold and hot air meet, fog will begin to appear. For a handmade tornado, use a clear jar with a lid that screws on tightly. Fill it with water and add a few drops of liquid dish detergent along with a few drops of food coloring. Twist the lid back on and swirl the mix around until the contents resemble a tornado.
Designate a week, a month or a season during which kids must create a pictoral weather journal. Take pictures in class or have each child take or draw pictures at home. Have the kids explain the weather depicted in each picture. Include impressions of the weather such as precipitation, temperature, cloud formations and anything else that stands out. Combine notes with photos and create individual weather diaries. One idea is to do a scrapbook-style book with sketches, stickers, and other embellishments.