Water Cycle in Action

Grades K-8

Materials Needed

• Sealable plastic bags (quart-sized zip-top)

• Permanent marker

• Water

• Blue food coloring (optional)

• Clear tape

• Small cups (optional for container version)

• Plastic container with lid (for alternate container method)

• Access to a sunny window or heat lamp

• Paper towels

A fun intro video to explain the water cycle: https://www.youtube.com/watch?v=TD3XSIE4ymo

Activity: Water Cycle in a Bag (25–30 minutes)

Instructions

1. Give each student a plastic bag.

2. Using a permanent marker, have them draw a sun, clouds, and a body of water on the outside of the bag.

3. Add about 1/4 cup of water and a drop of blue food coloring to represent a water source (optional).

4. Seal the bag tightly and tape it to a sunny window or place it under a heat lamp.

5. If you’re using a container:

   • Pour water into a clear container.

   • Place a small cup or rock in the center (to help collect condensation).

   • Seal the container with a clear lid or plastic wrap.

   • Set it in the sun or under a lamp.

What to Observe

• Over time, students will see evaporation (water disappearing from the bottom), condensation (droplets on the inside of the bag), and precipitation (droplets falling or rolling down).

• Use paper towels under bags or containers to catch drips.