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It’s simple to make a homemade thermometer with your kids using household items!


  • Mason jar with straw lid
  • Clear straw
  • Play dough or modeling clay
  • Water
  • Rubbing alcohol
  • Cooking oil (any kind)
  • Red (or other) food colouring


  • Add the food colouring, 1/4 cup water, 1/4 cup alcohol, and a tablespoon of oil into a mason jar and mix.
  • Stick the straw through the straw hole and tighten the lid onto the jar.
  • Mold a piece of play dough on the lid around the straw, which will hold the straw about half an inch from the bottom of the jar.
  • Place your DIY thermometer outside in the cold or in the fridge and inside the house and look at the difference in how high the liquid rises in the straw at different temperatures.

Spark Creative Learning!

Many commercial thermometers contain alcohol because alcohol has a low freezing point. As the temperature of the alcohol increases, it expands and causes the level within the thermometer to rise.

The level of the alcohol corresponds to the printed lines/numbers on a thermometer, indicating the temperature. This homemade version does something similar. However, with your homemade thermometer, you aren’t actually measuring temperature, just seeing temperature changes.

If you have a real thermometer, you can use it to make a scale on your homemade thermometer: let your bottle get to room temperature and then mark the straw with what the actual room temperature is. Then set the bottle in the sun or in the snow and do the same. Mark several different temperature levels and then watch your thermometer for a day and see how accurate it is.

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