Things You'll Need
Instructions
Fix the plastic ruler to the outside of a glass or plastic jar using a rubber band, making sure the bottom of the ruler is even with the bottom of the jar. Alternatively, you can place clear tape vertically on the outside of the jar and label measurements on it with a marker. Cover that piece of tape with another to prevent the markings from washing off.
Insert a funnel into the top of the jar, making sure the entire mouth of the jar is covered by it.
Place the jar in the rain away from trees or buildings, which could obstruct the collection of rainfall.
Measure the amount of rainwater collected by placing the jar on a flat, level surface and viewing how high, in inches or centimeters, the water reaches on the ruler. Record the results and empty the jar for its next use.