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Make Your Own Hygrometer - a Simple Science Experiment for Kids

A research enthusiast who is fascinated by science and forever on the lookout for educational experiments suitable for adults and kids.



Forecasting the weather with instruments

You can easily forecast the weather using a hygrometer. It is even possible to build a really simple hygrometer on your own. Imagine if you are going on a picnic and would like to know how the weather would be like. You turn to news channels or radio stations to get latest updates on weather so that you can step out of your house making all the necessary preparations like dressing accordingly, have necessary items on hand (like an umbrella for a rainy day).

Meteorologists, who are scientists who study the weather, make use of instruments like anemometer and hygrometer to predict the weather. Anemometer is used for measuring the speed of the wind whereas the hygrometer is to predict the amount of moisture in the air. Such weather predicting instruments are used in aircraft, in weather stations, ships and also weather balloons.

On this page you will get to see how you can make your own hygrometer to predict the amount of moisture in the air. This is a simple Science experiment suitable for kids and adults who take an ardent interest in knowing the simple basic Science facts. The idea is to get a better understanding of how an instrument like an hygrometer can be used to forecast the weather at a very basic level.

Making your own simple hygrometer - Science experiment for kids

Making your own simple hygrometer - Science experiment for kids

How to make your own hygrometer

Here are step by step instructions on how to create your own hygrometer. For the next 3 weeks, keep an account of the readings daily – read the hygrometer, record the reading and see how the weather would be like. This will give you an idea of what kind of weather to expect depending on the hygrometer reading. Your next task after keeping a record of results for the next 3 weeks, is to forecast the weather on your own using the hygrometer on the fourth week.

The following Science experiment is suitable for children who are 5th graders or above. To cut the wooden piece, parental guidance is needed.

Things you will need:

  1. A pencil
  2. A ruler
  3. A piece of thin card (16 cm x 4 cm)
  4. A piece of stiff card (24 cm x 30 cm)
  5. A pair of scissors
  6. Sticky tape
  7. A hair strand, about 25 cm long
  8. A wood piece (24 cm x 4 cm x 4 cm)
  9. Six drawing pins
  10. A coloured pen with a fine point
Scroll to Continue


  1. With the help of the ruler, draw an arrow which is around 13 cm x 2 cm on the thin card.
  2. Cut out the arrow from the thin card.
  3. Then attach the stiff card along the longer end of the wooden block with the help of drawing pins.
  4. Use sticky tape to attach one end of the hair strand to the top of the stiff card.
  5. The other end of the hair strand should be attached to the back of the arrowhead.
  6. Place this arrow on the stiff card and stretch it completely. Refer the picture to get an idea of how this looks like.
  7. Secure the arrow at the end to the stiff card with the help of a drawing pin.

Place this home made hygrometer outside. It is time to start taking readings! Take extra care to ensure that your hygrometer won’t topple over. When the Sun shines, mark on the card where the arrow is pointing. Aside this mark, write “dry”. You will see that the arrow would point lower, when it is a damper climate. In such cases, write “damp” next to the mark. This way you can keep note of the different weathers.

How does this hygrometer work?

Now that you have finished making your own hygrometer, you might be more curious of its functionality – how it is working the way it is. The answer is quite simple. On a damp day, your strand of hair has more capability of absorbing moisture from the atmosphere. The amount of moisture makes your hair strand stretch further on the thin card and hence, the arrow points lower than usual. In contrast, during dry days, the hair strand dries out as well and does not absorb moisture making it shorter. This makes the arrow point higher as opposed to those damp days.

Wet and Dry Bulb Hygrometer

Another advanced way of creating a hygrometer is shown in the video below. It explains how you can measure humidity in the air with the help of a wet and dry bulb hygrometer.

Weather experiment - Making your own hygrometer

© 2014 Kalpana Iyer


Kalpana Iyer (author) from India on October 04, 2020:

Thank you for reading my article on hygrometer science experiment, Umesh!

Umesh Chandra Bhatt from Kharghar, Navi Mumbai, India on October 04, 2020:

Interesting project for students.

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