How to Create a Working Model of the Water Cycle

Build a simple, hands-on water cycle model to help kids understand evaporation, condensation, and precipitation.

1. What You'll Need. Gather these common household items: a large clear bowl, a smaller bowl that fits inside, plastic wrap, a rubber band or tape, a small weight (like a coin or marble), warm water, and food coloring (optional). You'll also want good lighting and a warm spot near a window or lamp.
2. Setting Up Your Model. Place the small bowl in the center of the large bowl. Pour warm water into the large bowl around the small bowl, filling it about halfway up the sides of the small bowl. Add a few drops of food coloring to the water to make it easier to see what happens. Make sure no colored water gets into the small bowl.
3. Creating the Sky. Stretch plastic wrap tightly over the large bowl and secure it with a rubber band or tape around the edges. Place your small weight in the center of the plastic wrap, creating a dip that points down toward the small bowl. This represents the sky where clouds form.
4. Starting the Water Cycle. Place your model in a warm, sunny spot like a windowsill or under a lamp. The heat will cause the colored water to evaporate, rise up, and condense on the plastic wrap. Watch as tiny water droplets form on the underside of the plastic and eventually drip down into the small bowl, just like rain.
5. Observing and Learning. Check your model every 30 minutes to see the changes. Point out the evaporation happening from the warm water, the condensation forming on the plastic wrap, and the precipitation dripping into the small bowl. Notice that the water in the small bowl is clear, even though the original water was colored, showing how the water cycle naturally purifies water.