How to Create a Rain Gauge

Rain gauges are instruments used to measure the quantity of rainfall in a given time period. In existence since ancient Greece, many countries like Korea, India, England and the U.S. have developed various forms of rain gauges from simple machines to extremely scientific measuring tools. The most common style of rain gauge is a graduated cylinder, which is a straight-sided glass measuring jar. Other more complex styles include weighted gauges and tipping gauges. Rain can be measured in millimeters, centimeters or inches.

Things You'll Need

• Coat hanger or wire
• Rain gauge ruler
• Permanent marker
• Ruler with centimeter markings
• Straight-sided glass jar
• Funnel
• Tape

Instructions

1. Find a good location to place your rain gauge. This should be an area free of overhead obstructions like trees, roof overhangs or wires. Any of these can deflect rain and give you an inaccurate reading. Bend a coat hanger or wire to fit the measuring cylinder. Secure the wire holder to your measuring location.

2. Prepare your measuring standard. Make a ruler that marks the centimeter readings in half-centimeter increments. This will help the accuracy of your readings. Cover the ruler in plastic by taping over it with clear packing tape or placing it in a plastic bag to keep it waterproof.

3. Mark the inside of the glass with a waterproof, permanent marker if the cylinder doesn't already have etched measurements. Turn the glass so the measurement markings are visible from the front so you can check your readings. Otherwise, place the rain gauge ruler inside the glass, resting on the bottom of the cylinder. Tape it to the top of the glass to keep it from moving.

4. Place the glass cylinder in the holder. Steady it to make sure the container and the ruler are level. Check the security in the holder so that in a windy or heavy storm the glass will not fall over or shift.

5. Place the funnel into the cylinder. Use a flat-bottomed funnel so it rests evenly on the bottom of the cylinder. The funnel will help catch the rain and direct it into the measuring cylinder. After a storm, remove the funnel, take your measurements, record them and empty the glass for the next reading.

Tips & Warnings

• Use a washed, household glass jar from olives or jelly for a cost-effective measuring cylinder.

• Make sure the mouth of the funnel covers the whole opening of the measuring cylinder.

References

• USA Today---Rain Gauge
• Franklin's Forecast-Rain Gauge

Resources

• Miami Museum of Science---Rain Gauge
• Make and Use a Rain Gauge to Measure Precipitation