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  • Writer's pictureJenna Granger

Snow Castles

Updated: Dec 22, 2020

Experimenting with melting rates of snow and ice

Grade Level:



Physical Science:

  • Conservation of Energy & Energy Transfer

  • Structure & Properties of Matter

  • Chemical Reactions

  • Water on Earth

Tools & Materials

  • Snow

  • Small bucket or large measuring cup

  • Two rimmed baking sheets, cake/pie pans or turkey tins

  • Various cups & differently shaped containers (optional)

  • Timer

  • Camera or phone with built-in camera (optional)

  • Science notebook or paper & pencil

To Do & Notice

1. Question: Does shape affect the melting rate of snow?

2. Make a Claim: If you had the same amount (or volume) of snow, but shaped it differently would it melt slower or faster? Why or why not?

3. Test Ideas:  Using the steps below, build two snow castles of different shapes and compare the melting rate of each snow castle.

  • Go outside! Fill your small bucket (or large measuring cup) with snow. Remember the amount. You will need to use the same amount of snow to build your second snow castle.

  • Use the snow you collected to build snow castle #1 on your baking sheet, cake pan or turkey tin. Optional: Use the various shaped cups and containers to help create your castle. Get creative!

  • Once complete, set snow castle #1 aside, outside in the snow and shade to prevent melting.

  • Build snow castle #2 using the same amount of snow that you used for snow castle #1 and following the same instructions, but aim to make this castle a completely different shape than the first.

  • Once you complete both snow castles bring them inside and place equal distance from the fireplace or heater to melt.

  • Start a timer to track the melting rate of your snow castles.

4. Collect Data: In your science notebook or on paper, do the following:

  • Create a detailed drawing of each of your snow castles and label each.

  • Make a prediction of which castle you think will melt the fastest and why. Record your prediction in your notebook.

  • Make a prediction of how long you think it will take each snow castle to melt. Record your prediction in your notebook.

  • Option: Take a photo of each snow castle at the starting point and again at regular intervals (every 15 minutes) throughout the melting process. Or start a timelapse video of your castles and continue through the melting process.

  • Record the time it takes for each castle to melt.

5. Analyse & Interpret Data:

  • Continue to observe your snow castles throughout the melting process. Describe what happened in your science notebook.

  • Were your predictions correct?

  • Why do you think the one castle melted quicker than the other castle? What surprised you?

6. Communicate Findings:

  • Return to the question. Does shape affect the melting rate of snow? What did you learn? Write a conclusion statement in your science notebook. (Example: I found that shape does affect the melting rate of snow. I learned that snow castles that are more spread out melt faster than snow castles where the snow is lumped together.)

  • Post photos of your snow castles and which one melted first on social media and tag us @sweptahoe on Instagram and/or to @swep4 on Facebook. Be sure to hashtag and follow #SWEPsnippets. If you cannot post directly yourself, send SWEP your snow castle photos (

What’s Going On

  • Snow is made out of water. Water is made out of water molecules. Water molecules are made out of 2 hydrogen atoms and one oxygen atom (That’s why water is often called H2O).

  • When water molecules are exposed to heat energy they can change states.

  • To learn more about the 3 states of water, watch this video.

  • To learn more about what water molecules look like when they are in different states, watch this Video.

  • In the snow castle experiment, you should have noticed that snow castles with a more spread out structure melted faster. This is because more spread out means there is greater surface area and therefore more water molecules are exposed to the heat energy from the fire, heater or warm air. The exposure to heat energy allows the molecules to move as the water changes state from solid to liquid. The more compacted snow castles have more water molecules trapped inside, away from the heat energy and therefore melt more slowly.

Going Further

Try more melting activities to learn more:

  • Question: Will ice that is made from the same amount (volume) of water and frozen in the same shape, melt at the same rate? Test Idea: Get two plates and two ice cubes, set one ice cube on each plate. How long do you think it will take them to melt? Write your claim in your notebook. Do you think they will both finish melting at the same time?

  • Question: If the same amount (volume) of water is frozen into different shapes, will they melt at the same rate? Test Idea: Get three different shaped, freezer safe containers. Fill each container with the same amount of water ( ½ cup) and put in the freezer. Once frozen remove and take each ice structure out of its container (careful not to break) and put on separate plates. Write your claim: Do you think they will melt at the same time? If not which ice structure do you think will melt the fastest and why? Watch this timelapse video of a similar experiment to see another scientist’s results.

  • Question: How does salt affect melting rates of ice? What happens when you put salt onto an ice cube? Test Idea: Get an ice cube and some salt and find out! To see what happens even more clearly add a dash of food coloring before you add the salt to the icecube, and then again after you add the salt! Watch this video to learn about why we use or don’t use salt on our roads in the winter.

Ever wanted to live or stay in an ice castle? Watch this video of 10 Magical Hotels Made Entirely of Ice.

Thanks to our partners at Winter Wildland Alliance's SnowSchool and Tahoe Cross Country Ski Education Association for supporting student’s snow science learning activities.

Please review SWEP's Terms of Use prior to using this resource.



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