Measure rainfall
Make a simple rain gauge from a plastic bottle, measure daily rainfall, record amounts, and compare results to learn about weather.
About this activity
Make a simple rain gauge from a plastic bottle, measure daily rainfall, record amounts, and compare results to learn about weather.
What you need
Step by step
- 1
Step 1
Gather all your materials and bring them to a flat workspace so you are ready to build your rain gauge.
- 2
Step 2
Peel the label off the bottle so you can see through the plastic clearly.
- 3
Step 3
Ask an adult to help you cut the top third off the bottle so you have a funnel piece and a base piece.
- 4
Step 4
Put a few small stones or pebbles into the bottom of the bottle base to keep the gauge from tipping over.
- 5
Step 5
Turn the top piece upside down and fit it into the base so it makes a funnel that catches rain.
- 6
Step 6
Wrap waterproof tape around the seam where the two pieces meet to hold them securely together.
- 7
Step 7
Use the ruler to draw small tick marks up the side of the bottle at every centimeter starting from the bottom.
- 8
Step 8
Write the numbers next to the tick marks with the permanent marker so you can read how many centimeters of rain fell.
- 9
Step 9
Take your rain gauge outside and set it on a flat open spot away from trees and roof eaves so it catches real rainfall.
- 10
Step 10
At the same time each day look at the water level in the gauge and read the closest centimeter mark.
- 11
Step 11
Write the date and the rainfall amount in your notebook so you can compare days.
- 12
Step 12
After you record the amount pour the water out so the gauge is ready for the next day of rain.
- 13
Step 13
Take a photo of your rain gauge and your recording sheet and share your finished creation and findings on DIY.org
Fun facts
How do I make a simple rain gauge and measure rainfall with my child?
To measure rainfall, cut the top off a clear plastic bottle and invert it into the base to form a funnel, or simply remove the top. Mark a ruler or use tape to add measurement lines in millimeters or inches, starting at zero at the bottom. Place the gauge outside on level ground away from buildings and trees. Record daily rainfall in a notebook at the same time each day, emptying and resetting after reading.
What materials do I need to make a DIY rain gauge?
You'll need a clear 1–2 liter plastic bottle, scissors or a utility knife (adult use), waterproof marker or masking tape and a ruler for measurements, stones or sand to weigh the base, a stick or tray to stabilize, and a notebook and pen for daily records. Optional: a funnel, measuring cup for calibration, and waterproof labels. Gather everything before setting up to keep the project organized and safe.
What ages is measuring rainfall with a homemade rain gauge suitable for?
This activity suits children aged about 4–12. Preschoolers (4–6) enjoy helping with pouring, marking, and recording with close adult supervision. Elementary kids (7–10) can cut, measure, and maintain the gauge with guidance on safety and measuring units. Older children (11–12+) can design experiments, compare results, and graph data more independently. Always supervise tools like scissors or knives and discuss weather safety when working outdoors.
What are the benefits of measuring rainfall and variations to try?
Measuring rainfall teaches observation, data recording, and basic science—helping children learn measurement, patterns, and cause-effect. It boosts patience and math skills when comparing totals and making simple graphs. For variations, try different gauge locations, use colored water to test evaporation, or build multiple gauges to compare microclimates. Always empty the gauge after reading, secure it from animals, and check local safety guidelines during storms.
Watch & Learn
Need help?
What can we use if we don't have waterproof tape or small stones?
If you don't have waterproof tape, use duct tape or clear packing tape to seal the seam, and if you don't have small stones put marbles or a handful of sand in the bottle base to weigh it down.
My funnel piece keeps falling out or leaking—what can I do?
After you cut the top third off and fit it upside down into the base, push the rim deeper to create a snug fit, rewrap the seam with extra waterproof tape, and make sure there are pebbles in the bottom so the gauge doesn't tip and spill.
How can I adapt this activity for younger children or older kids?
For young children have an adult do the cutting and pre-draw centimeter tick marks for them to read and record in the notebook, while older kids can add millimeter marks with the ruler and permanent marker and track trends over time.
How can we extend or personalize the rain gauge project?
Decorate the bottle after peeling the label, tape a paper ruler with centimeter marks inside for easier reading, compare two gauges placed in different spots, and remember to photograph your rain gauge and recording sheet to share on DIY.org.