SGUK Outdoor Skills Challenge 30: Make a Rain Gauge

Rainfall affects everything from ground conditions on a walk to how quickly streams and rivers can rise. Making a simple rain gauge gives you a way to measure what’s falling where you live, rather than relying on how wet the ground looks.

For this challenge, you’ll make a rain gauge of your own, place it somewhere suitable and start keeping a record of the rainfall.

Your Challenge

Build a simple rain gauge from a recycled plastic bottle, then use it to collect and measure rainfall. Record your readings over several days and see how the amount changes.

What You’ll Need

• A clear, empty plastic bottle.
• Scissors.
• Sticky tape.
• A ruler and permanent marker.
• A few small stones to help stabilise the gauge, if needed.
• A notebook or phone to record your readings.

Take the Challenge

1. Prepare the bottle. Ask an adult to help if needed, then carefully cut the top third off the bottle. Keep both pieces.
2. Make the funnel. Turn the top section upside down and place it inside the bottom section. Secure it with tape. This helps guide the rain into the container and reduces any splashing.
3. Add a measurement scale. Use a ruler to mark a scale in centimetres and millimetres on the side. Make sure you start measuring from the actual bottom of the collecting area. If the base is uneven, add a little modelling clay or another waterproof material to create a flat starting point, then mark zero above it.
4. Choose a suitable position. Place the gauge on level ground in an open area, away from trees, buildings and overhanging roofs. These can block rainfall or direct extra water into the container. Secure it so it cannot easily blow over.
5. Take your readings. Check the gauge at the same time each day. Record the water level in millimetres, then empty it ready for the next reading.

Keep your gauge upright and check that it hasn’t moved after strong winds. If it tips over or water spills out, make a note that the reading may be unreliable.

Check Your Results

After several days, look back at your rainfall records and check that you can:

• Make and position a simple rain gauge.
• Read and record the water level in millimetres.
• Compare rainfall between different days.
• Explain why the position and stability of the gauge affect the results.

Remember that a homemade bottle gauge is a simple experiment, not a precision weather instrument. Its shape and opening can affect how accurately it measures rainfall.

For a more detailed guide, follow the Met Office instructions for making your own rain gauge.

Complete the Challenge

Take a photograph of your finished rain gauge in its chosen position. Record at least one rainfall reading, and ideally collect readings over several days to show that you have tested it.

How to Submit Your Challenge

1. Go to your SGUK member profile.
2. Open the Social Activity area.
3. Upload a photograph of your rain gauge and, if possible, your recorded results to your activity wall.
4. Add the hashtag #SGUKChallenge30.
5. Share your post for evidence verification.

Once you’ve shared your evidence and it has been verified, the SGUK Outdoor Skills Challenge 30 is complete and the completed challenges figure will be updated on your profile.

Challenge 30 Checklist

Want to Push Yourself?

Keep a rainfall record for a full week. Add up your daily readings to calculate the total rainfall you measured, then compare your results with a local weather report. The figures may differ because of the location and design of your gauge, but the comparison is a useful way to think about how weather observations are collected.

What’s Next?

For your previous challenge, revisit SGUK Outdoor Skills Challenge 29: Build a Shelter Using Only One Tarp and One Rope. Think about how your rainfall readings could help you understand the conditions your shelter might need to cope with.

Each SGUK Outdoor Skills Challenge can be completed in any order, so keep experimenting and developing your outdoor skills.

Learn. Practise. Master.

That’s what the SGUK Outdoor Skills Challenge is all about.