STEM Activities for Rainy Days at Home

When rain keeps the family indoors, it is the perfect opportunity for hands-on STEM learning. These activities use common household items to explore science, technology, engineering, and mathematics concepts. Best of all, they are engaging enough to keep children occupied for hours while sneaking in valuable educational content.

Quick-Start Activities (15-30 Minutes)

These shorter activities are perfect when you need something engaging quickly without extensive setup or cleanup.

Rainbow Walking Water

This classic experiment demonstrates capillary action in a visually stunning way. Arrange seven clear glasses in a row. Fill glasses 1, 3, 5, and 7 with water, adding red food colouring to glasses 1 and 7, yellow to glass 3, and blue to glass 5. Connect each glass to its neighbour using strips of paper towel, draping one end into each glass.

Over the next few hours, watch as the coloured water travels up the paper towels and into the empty glasses, mixing to create orange, green, and purple. This is an excellent activity for teaching about absorbency, colour mixing, and patience in scientific observation.

Kitchen Sink Density Tower

Explore density by creating a colourful tower of liquids in a tall glass. Layer honey, corn syrup, dish soap, water (with food colouring), vegetable oil, and rubbing alcohol. Each liquid has a different density, so they stack on top of each other without mixing.

Once your tower is complete, drop small objects into it and predict where they will settle. A grape will sink through some layers but float on others. A small bolt will drop straight to the bottom. This activity generates rich discussions about why some things float and others sink.

Static Electricity Butterfly

Cut a butterfly shape from tissue paper and place it on a flat surface. Rub a balloon vigorously against your hair or a wool sweater to build up static electricity. Hold the balloon close to the butterfly without touching it and watch the wings lift toward the balloon.

Experiment with different materials—which ones work best for creating static? How far away can the balloon be and still move the butterfly? This simple activity introduces concepts of electric charge that will be built upon in later physics education.

Extended Projects (1-2 Hours)

These more involved activities provide deeper learning experiences and can occupy children for longer periods.

Marble Run Engineering Challenge

Challenge children to design and build a marble run using only cardboard tubes (from paper towels and wrapping paper), tape, and scissors. Set specific goals: the marble must take at least 10 seconds to reach the bottom, include three direction changes, and land in a designated cup.

This activity develops engineering thinking as children iterate on their designs. When a section does not work as expected, they must diagnose the problem and implement solutions. Encourage them to sketch their design before building and to document what they learn from each attempt.

Kitchen Chemistry: Homemade Slime Investigation

Making slime is not just fun—it is a lesson in polymer chemistry. Create several batches of slime with different ratios of ingredients to investigate how proportions affect the final product. Use a basic recipe of glue, water, and borax solution, then systematically vary one ingredient at a time.

Create a data table recording the amount of each ingredient and the resulting slime properties: Is it stretchy or stiff? Does it hold its shape or flow? Can you bounce it or does it break apart? This scientific approach transforms a popular craft into genuine inquiry-based learning.

For younger children or those sensitive to borax, contact lens solution with baking soda creates a similar slime without the stronger chemicals.

Bridge Building Challenge

Give children a limited supply of materials—perhaps 50 paddle pop sticks, 20 rubber bands, and some string—and challenge them to build a bridge that spans a 30-centimetre gap between two chairs. Test the bridge's strength by gradually adding weight until it fails.

This challenge introduces structural engineering concepts including load distribution, triangular bracing, and material properties. After the first bridge fails, allow children to rebuild with lessons learned. Compare different designs and discuss why some held more weight than others.

All-Day Projects

For those truly rainy days when you need activities that can stretch across hours with breaks in between, these projects offer sustained engagement.

Growing Crystals

Crystal growing teaches patience alongside chemistry. Dissolve as much sugar or salt as possible in hot water to create a supersaturated solution. Hang a string or pipe cleaner in the solution, then set it aside in a location where it will not be disturbed.

Over several days, crystals will form on the string as the water evaporates. Check the crystals each day and record observations in a science journal. Discuss why crystals have regular geometric shapes and why they grow larger in undisturbed conditions.

For faster results with bigger crystals, use borax dissolved in hot water. Beautiful crystal formations can appear within hours, with impressive growths overnight.

Weather Station Setup

A rainy day is actually perfect for starting a weather observation project. Create simple instruments using household items: a rain gauge from a plastic bottle with centimetre markings, a wind vane from cardboard and a straw, and a barometer from a jar with a balloon stretched over the top.

Set up a recording chart and commit to taking measurements at the same time each day. Over weeks and months, children can spot patterns in their data and begin making simple weather predictions. This ongoing project teaches measurement, data recording, and pattern recognition.

Adapting Activities for Different Ages

Most STEM activities can be simplified or extended to suit different age groups:

• Younger children (4-6): Focus on observation and description. Ask about colours, textures, and changes. Keep sessions short with lots of hands-on interaction.
• Primary age (7-10): Introduce measurement and comparison. Encourage predictions before experimenting and recording results afterward.
• Older children (11+): Add variables and controls. Challenge them to design fair tests and analyse what factors affect outcomes.

Making the Most of Rainy Day Learning

The key to successful rainy day STEM activities is preparation. Keep a box of supplies ready—cardboard tubes, balloons, food colouring, glue, tape, and other basics that support multiple activities. When rain strikes, you are ready to pivot from outdoor plans to indoor exploration.

Remember that the goal is engagement and curiosity, not perfection. Let children lead their own investigations when inspiration strikes. Some of the best learning happens when children ask "What would happen if...?" and have the materials and freedom to find out.

Rainy days need not be boring days. With a bit of preparation and creativity, they can become some of the most memorable learning experiences of childhood.