Rain is measured by using a rain gauge. When rain falls, many times it is absorbed into the earth, making it hard to figure out how much rain fell. Weather forecasters use rain gauges to provide viewers with accurate rain amounts and determine if your area is at risk of flooding. Make your own rain gages to measure rainfall, just like a meteorologist, and use the information gathered to predict local weather.
A rain gauge is a tool used for measuring the amount of accumulated precipitation, or rain, in any location at any time. According to the Weather Shack, the ideal site for a rain gauge is in an open area that is protected from wind or tall buildings. Wind can affect the amount of rain gathered in a rain gauge due to blowing the rain, and tall buildings may obstruct the falling rain.
According to the Royal Meteorological Society, King Sejong from Korea invented the first standardised rain gauge in 1441. The reason for the invention was to have an official tool to assess land taxes based on a farmer's potential harvest, which would be affected by how much rain it received.
Evolution of the Rain Gauge
In time, the rain gauge evolved to what Sir Christopher Wren invented in 1662, which was the mechanical self-emptying, tipping bucket rain gauge. According to the Weather Shack, this is the main type of rain gauge used today for measuring rain in most home weather stations.
When the rain is pounding down, a rain gauge tells meteorologists if the amount of rain is low, high or normal for that time of year. Meteorologists can also use the information to predict rainfall for the future. According to the National Aeronautics and Space Administration, meteorologists use rain gauges, temperature readings, atmospheric patterns and wind measurements to predict the weather.
Making a Rain Gauge
A rain gauge can be purchased at your local home and garden store, but a homemade rain gauge can be made easily by reusing a 2-liter plastic bottle. According to the National Gardening Association, you can make a rain gauge by cutting the top off a 2-liter plastic bottle--ask an adult to help if necessary--and placing the bottle top into the bottom of the bottle to act as a funnel for the rain. Place the rain gauge outside to collect precipitation. After a big rain, measure the amount of rain by placing a ruler against the side of the rain gauge and measuring to the closest tenth of an inch.
According to Beginner's Guide, 1 inch of rain in a rain gauge equals 4.7 gallons of water per square yard. Per square acre, it equals 22,651 gallons of water, which weighs 102.7 tons. One inch of rain over a square mile is 14.5 gallons of water.