Rainbow activities: Look

Make a barometer

Scientists use a barometer to help them understand what the weather will be like. Why don’t you try making one and see if you can too?

You will need:

Scissors, tape, a balloon, a jar, a rubber band, a straw, a piece of paper and a pen

A home-made barometer

  • Cut the top off the balloon and throw away the part you blow into.
  • Stretch the balloon over the top of the jar and hold it in place with the rubber band.
  • Place the straw across the top of the jar so that a third of the straw is hanging over the edge. Stick the straw to the balloon with tape.
  • Put your barometer on a flat surface somewhere inside, next to a wall and tape a piece of paper or card to the wall behind it. (Don’t forget to ask permission before you attach anything to the wall!)
  • Draw a line where the straw rests against the card and label it Medium.
  • Then draw two more lines on the piece of card that are about a centimetre apart above and below the medium line label the top one High and bottom one Low.
  • For the next few days check the straw often and mark its position on the paper for a few days.
  • Add notes to tell you what the weather is like next to the marks.
  • Examine the paper after several days. Check the markings and the weather statements you've put next to them. What is the weather like when the straw is high? What is it like when it is low?

The barometer works by measuring air pressure. Normally, high air pressure means that we will have good weather and low pressure means that we could be in for storms and rain. Why not keep track over the course of a week and see if you can start predict what the weather will be like?.