How do they measure rainfall

Rainfall, snow and other weathery downfall is measured by a rain gauge. This instrument tells us how many inches of water would stay on the ground if none of it sank in or ran away. It gathers the moisture as it falls onto a small circular area and measures its depth in inches.

The Weather Bureau collects the figures from gauges at widely separated points and uses them to estimate the rainfall over a large area.

The gauge is placed on a level place away from trees and buildings. The moisture falls into a metal cylinder. The base of the cylinder opens into a narrower cylinder which is marked with a scale of inches. The scale gives the depth of the downpour which fell upon the open area at the top of the rain gauge.