How to Measure Rain with a Rain Gauge - Rest Nova Site

How to Measure Rain with a Rain Gauge

How to Measure Rain with a Rain Gauge


Until the invention of the rain gauge, accurate rainfall measurement had been difficult due to the uneven distribution of precipitation across regions.

Measuring rainfall provides valuable information that can help prevent and prepare for natural disasters. Some other benefits include:

  • Provides rainfall database.
  • Provides the information required to monitor potential conditions like flooding and drought.
  • It efficiently predicts the best planting season and monitors soil conditions.
  • Over time, rainfall records make monitoring climate change and weather patterns easy.

What is a Rain Gauge?

Rain gauges are instruments meteorologists use to measure precipitation in a particular place over a given period, usually 24 hours. Rain gauges can also measure snow, mist, dew, and sleet.

Rain gauges vary in their types – there are two major types; Analog rain gauges and Digital rain gauges – but they generally work under two operating conditions, either manual measurement or automatic measurement. Rainfall can be measured in inches, millimeters, or centimeters, depending on the calibration of the rain gauge.

Components of a Rain Gauge

Three essential rain gauge parts allow the device to measure rain effectively.

  1. A funnel
  2. Measuring tube
  3. An overflow tube

Each part plays a vital role in the collection and measurement of precipitation. The funnel is specially coated to prevent rain from wetting, which may prevent accurate measurement.

The funnel directs the water into the measuring tube and magnifies it by 10, which enables the observer to record rainfall at the nearest 0.01.

The measuring tube will hold only one inch of rainfall, depending on the size of the rain gauge. Some rain gauges have a larger capacity and can hold up to 150 mm, 230 mm, and 250 mm of rainfall.

Using a Rain Gauge

The measurement of your rain gauge wouldn’t be accurate if you do not place the device in the correct location. It is best to place your rain gauge in an open area at least twice the distance from the height of the nearest obstruction. For example, the device will be 30 feet away from a 15-foot tall pole or tree.

Set the rain gauge directly into the ground or to a post, and ensure that the top of the device is level to ensure that retained precipitation can be drained after recording it.

Approach the device after rainfall, and record the rainfall collected in the measuring tube. When taking measurements, it is vital to read below the meniscus and record it on the rainfall chart.

Rainfall can be heavy, and the measuring tube can overflow. When the overflow tube collects the excess water, record the water in the tube, empty the tube, pour the overflowed water into the measuring tube, and record it. Continue until the overflow water is thoroughly measured and add up the totals. Record the rain gauge at the same time of the day for a given time.

Using a rain gauge is relatively easy, but the slightest mistake can affect the accuracy of your measurement. It’s why you should get one that will be easy to read and require less dexterity. You can get these rain gauges online.