How to Make a Sundial in Your Yard - Printable activity sheet for kids
How did people tell time before clocks and watches were invented? They looked to the sky!
Long before modern clocks, people used the Sun and shadows to keep track of the time. In this simple outdoor science activity, you can make your very own sundial using just a stick, a few rocks, and a sunny day.
It's a fun way to learn about the movement of the Sun, shadows, Earth's rotation, and ancient timekeeping. Even better, you can watch your sundial change throughout the day and make predictions about where the shadow will appear next.
What You'll Need
You don't need any special science equipment for this experiment.
Materials
- ☀️ A sunny day
- A flat, open area outdoors
- A straight stick
- Several small rocks
- A clock or watch
That's it! The Sun does most of the work.
How to Make Your Sundial
Step 1: Find a Sunny Spot
Choose a flat, open area where the Sun will shine for several hours.
Make sure there aren't too many trees, buildings, or other objects that will block the sunlight and cover your sundial with shade.
Step 2: Place the Stick
Push the stick firmly into the ground.
Try to make it stand as straight up and down as possible. This stick will act as the main part of your sundial. The shadow it creates will help you track the time.
Step 3: Mark the First Shadow
Look at your clock and write down the current time.
Now look at the shadow made by the stick. Place a small rock at the tip of the shadow to mark its position.
You can also draw a line from the base of the stick to the rock.
This is your first time marker.
Step 4: Watch the Shadow Move
Now comes the fun part!
Return to your sundial every hour and check the shadow.
Each time you visit, place another rock at the tip of the shadow and write down the time.
Try predicting where the shadow will be before you check!
Will it be longer or shorter? Will it move to the left or the right?
Step 5: Create Your Time Markers
After several hours, you'll have a collection of rocks showing where the shadow appeared at different times.
Connect each mark to the base of the stick with a line. Write the corresponding time next to each mark.
Congratulations — you've made a sundial!
How Does a Sundial Work?
You might be wondering: Why does the shadow move if the stick isn't moving?
The answer has to do with Earth's rotation.
As Earth rotates, the Sun appears to move across the sky during the day. Because the Sun's position changes, the shadow cast by the stick also changes its direction and length.
In the morning, the shadow is usually quite long. As the Sun climbs higher in the sky, the shadow becomes shorter. Later in the afternoon, the shadow becomes longer again as the Sun appears to move toward the horizon.
The shadow can therefore act like the hand of a clock.
Can You Predict the Shadow?
Turn your sundial into a prediction game!
Before checking your sundial, ask:
- Where will the shadow be in one hour?
- Will the shadow be longer or shorter?
- Which direction will it move?
- When will the shadow be shortest?
- What do you think will happen tomorrow?
Write down your predictions and then check whether you were right.
Try This Experiment Again
A sundial can teach you even more if you observe it on different days.
Try making observations:
- In the morning
- Around midday
- In the afternoon
- On different days of the week
- During different seasons
Keep a shadow journal and record the time, the length of the shadow, and where it appears.
You can even measure the shadow with a ruler and make a simple graph showing how its length changes during the day.
A Fun Historical Connection
People have been using shadows to understand and measure time for thousands of years. Ancient civilizations developed different types of sundials to track the movement of the Sun.
By making your own sundial, you're using the same basic idea: watch the Sun, observe the shadow, and use what you see to measure time.
A Quick Tip About Noon
Around solar noon, the Sun reaches its highest point in the sky for that location, so the stick's shadow is generally at or near its shortest length for the day.
However, solar noon isn't always exactly 12:00 on your clock. Your clock time can differ because of your location, time zones, and daylight-saving time.
So don't worry if your sundial doesn't perfectly match your watch. The goal of this experiment is to observe the pattern and understand why the shadow changes.
What Did You Discover?
A simple stick and a few rocks can turn your backyard into a science laboratory!
By making a sundial, you've explored astronomy, timekeeping, shadows, and Earth's rotation — all with materials you can find around your home.
Next time you see a shadow moving across the ground, stop and think:
What time could it be? And where will the shadow be next?
