December and January can be a tough stretch for science teachers. Students are distracted by the holidays, the days are short, and engagement dips. Winter science experiments for high school are a great fix: they use the season itself, cold air, ice, snow, and salt, to teach real chemistry and physics concepts that show up on tests.
Every experiment below uses inexpensive materials, fits in a single class period, and connects to standard topics like phase changes, heat transfer, gas laws, and density. Pick one for the week before break, the first week back, or a snow day assignment students can try at home.
In this guide7 sections
Phase changes and solutions
1. Freezing point depression ice cream
Put milk, sugar, and vanilla in a small sealed bag, place it inside a larger bag filled with ice and rock salt, and shake for about ten minutes. Students measure the temperature of the ice and salt mixture and compare it to plain ice. The salt lowers the freezing point of water, so the mixture gets colder than 0 °C and pulls enough heat out of the milk to freeze it. Check your school’s food policy before letting students taste.
2. Salt vs. sugar vs. sand on ice
Place equal ice cubes on three plates and sprinkle each with the same mass of salt, sugar, or sand. Students time how fast each melts and discuss why road crews use salt and why sand is used for traction instead of melting. This is a strong lead-in to colligative properties.
3. Frost on a can
Fill a metal can with crushed ice and a few spoonfuls of salt, stir, and wait. Within minutes, frost forms on the outside. Students explain deposition: water vapor in the room turns directly into ice on the very cold surface. Compare with a can of plain ice, which usually collects liquid condensation instead.
Heat transfer
4. Insulation design challenge
Give teams an identical ice cube and a limited set of materials such as foil, newspaper, felt, bubble wrap, and cups. The goal: design a container that keeps the ice from melting longest. Teams predict, test, and graph mass of ice remaining over time. This engineering challenge works well with structured group work roles.
5. Do mittens make heat?
Place a thermometer inside a mitten and another on the desk, and record temperatures for 20 minutes. Many students predict the mitten will warm up. It does not, because mittens trap heat produced by a body rather than generating heat. It is a quick way to address a common misconception about insulation.
6. Snow-to-water ratio
If you have snow, have students pack a measured volume into a container, let it melt, and measure the water. Fresh snow is mostly air, so the liquid volume is much smaller. Students calculate a ratio and discuss why wet, heavy snow and dry, fluffy snow give very different results. No snow? Use shaved ice from the cafeteria and compare.
Gas laws and density
7. Balloon in the cold
Measure the circumference of an inflated balloon, put it outside or in a freezer for 15 minutes, and measure again. The balloon shrinks in the cold and expands as it warms. Students connect the change to Charles’s law. Follow up with the free PhET Gas Properties lab to see the particle view.
8. Why ice floats
Freeze a known mass of water in a graduated container and compare volume before and after freezing. Water expands as it freezes, so ice is less dense than liquid water. Discuss what this means for lakes and aquatic life in winter, and connect to the States of Matter simulation lab.
Earth and space
9. Solstice sun angle model
Shine a flashlight on graph paper at a steep angle and then at a low angle, and count the squares lit up each time. The same light spread over a larger area means less energy per square, which models why winter days are colder. It pairs naturally with our winter solstice activities.
10. Snowflake crystal growth
Grow crystals on pipe-cleaner snowflakes in a hot, saturated borax solution overnight (with goggles and adult supervision for the hot water). Students observe crystal shapes and discuss solubility and how it changes with temperature.
Quick planning table
| Experiment | Main concept | Time | Key materials |
|---|---|---|---|
| Freezing point ice cream | Colligative properties | 30 min | Bags, ice, rock salt, milk |
| Salt vs. sugar vs. sand | Freezing point depression | 25 min | Ice cubes, salt, sugar, sand |
| Frost on a can | Deposition | 15 min | Metal can, ice, salt |
| Insulation challenge | Heat transfer, engineering | 50 min | Ice, assorted insulators, scale |
| Mitten test | Insulation misconception | 20 min | Mittens, thermometers |
| Snow-to-water ratio | Density, measurement | 30 min + melt | Snow, graduated cylinders |
| Balloon in the cold | Charles’s law | 25 min | Balloons, string, ruler |
| Why ice floats | Density, phase change | Overnight freeze | Graduated container, freezer |
| Solstice sun angle | Seasons, insolation | 20 min | Flashlight, graph paper |
| Borax snowflakes | Solubility, crystals | 20 min + overnight | Borax, pipe cleaners, hot water |
Want more seasonal ideas month by month? See our classroom activities calendar.
Frequently asked questions
What is the easiest winter science experiment for a big class?
The salt vs. sugar vs. sand ice test needs almost no setup, works with any group size, and produces clear, measurable results in one period.
Can these experiments be done without snow?
Yes. Every activity except the snow-to-water ratio works with ice from a freezer, and that one can use shaved ice as a substitute.
Are these experiments safe for high school?
With normal lab safety they are. Ice and salt mixtures can get cold enough to irritate skin, so use gloves or towels, and wear goggles when handling hot borax solution.
How do I grade a winter science experiment?
Have students submit a short CER (claim, evidence, reasoning) paragraph with a data table or graph. It keeps grading quick and focuses on the science behind the fun.
Bring the season into the lab
Winter does not have to be a slump. These winter science experiments give students a reason to pay attention in the coldest weeks of the year, and every one ties back to concepts they need to master. Choose one, gather some ice and salt, and let the season do the teaching.
