Rising Water Science Experiment for Kids

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If you’re looking for a simple but impressive science activity, this Rising Water Experiment is a kids’ favorite. It takes only a few household materials and vividly demonstrates air pressure, temperature change, and how storms form. This is a perfect STEM lesson for homeschool, classrooms, or a rainy afternoon at home.

Watch it in Action:

Supplies You Need

Large Cork
Wooden Matches
Small Plate
Tall Glass
Water
Lighter or Match

How to Do the Rising Water Experiment

1. Prep the cork

Cut the cork lengthwise so it has a flat bottom. Using a toothpick or skewer, poke three small holes into the top of the cork. Insert a wooden match into each hole so they stand upright.

2. Set up the plate

Place the cork in the center of the plate, then pour in enough water to cover the bottom of the plate, about ½ inch deep.

3. Light the matches

Light the three matches. They should stay lit and upright in the cork.

4. Cover with the glass

Quickly place the tall glass straight down over the cork and into the water.
Watch carefully!

What happens?

• The matches go out.

• The water climbs up inside the glass.

• The cork rises with it.

It’s a dramatic demonstration of air pressure at work!

Why Does the Water Rise?

This experiment demonstrates air pressure and changes in density.

1. The air inside the glass heats up

When the flame burns, the air inside the glass becomes warm.
Warm air molecules move faster and spread out → this makes the air less dense.

Some of the air even escapes from under the glass before the water seals it.

2. The matches use up the oxygen

When the oxygen is consumed, the flame goes out.
The air inside cools down quickly.

3. Cooling creates lower air pressure

Cooler air = slower-moving molecules that take up less space → lower pressure inside the glass.

4. Outside air pushes the water upward

Because the air pressure outside the glass is stronger than the air pressure inside it, the outside air pushes the water up into the glass to equalize the pressure.

This is why the cork floats upward with the water level!

How This Connects to Weather, Wind & Storms

This is a fantastic visual model for how weather systems work.

• Warm air rises because it is less dense.

• Cooler air rushes in to fill the space → this movement creates wind.

• When warm ocean air rises rapidly (like in hurricanes), it can lift large amounts of water vapor, creating massive storm systems.

• Differences in temperature and air pressure drive storms, fronts, and wind patterns.

This experiment is a small-scale version of how rising warm air creates powerful weather changes.

STEM Extensions & Variations

Try one of these to turn it into a full lesson:

1. Use different-sized glasses

Does the water rise higher in a narrow jar vs. a wide one?

2. Add food coloring to the water

Makes the rising water extra easy to see.

3. Try using one match vs. three

See how flame size affects heating and pressure changes.

4. Tie in a weather lesson

Sketch a diagram of warm fronts and cold fronts using arrows to model rising and sinking air.

I have a huge list of Science Projects and STEM Activities. Check out more of them!

See More Water Science: 25 Water Science Experiments and Activities!