Science Smarts: Thermometer

By Patty Rooks on March 14, 2026.

I do not know about you, but I often look at the weather before I leave in the morning. This helps me know what I should wear so I am prepared for anything – especially this time of the year. The weather can be quit unpredictable. Of course, when I looked out the window this morning, my thermometer was broken – well, I had better figure out a way to make my own. Let’s get started!

*Remember to ask an adult before doing this experiment.

Materials

– Water

– Red food colouring

– Empty pop bottle

– Plasticine

– Straw

– Piece of stiff paper or cardboard

– Pen

– Tape

Procedure

1. Fill the pop bottle 3/4 full of room temperature water.

2. Add a couple of drops of red food colouring to the water.

3. Put the lid on the bottle and shake the water up so the food colouring can be mixed in.

4. Remove the lid and wipe up any spills on the outside of the bottle.

5. Take a straw and place it half the length of the straw into the bottle.

6. Place a piece of plasticine around the straw to hold it into place.

7. Cut a piece of paper out, that is the length of the straw sticking out of the bottle.

8. Draw horizontal lines on the paper one centimetre apart and label.

9. Tape the piece of paper onto the straw.

10. This “scale” will help you read the thermometer.

11. Try taking the temperature at different locations.

What is going on?

Did you know that temperature is a measure of the degree of heat or cold in the air. A thermometer can measure the degree of heat.

The higher up on the scale, the warmer the temperature. The lower on the scale, the colder the temperature.

Do not forget to register for the upcoming Regional Science Fair at Medicine Hat College. The link is: https://forms.gle/YmQuZ7cEkfAtZDM99 . I hope to see you there on Saturday, March 21!

Patty Rooks, senior scientific consultant Praxis Science Outreach Society. Praxis is located in the Community Futures Entre Corp Building at #202 556 Fourth St. SE, Medicine Hat, Alberta, T1A 0K8. For all your science needs, please email praxis@praxismh.ca.

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