What instrument measures the amount of rainfall at a location?

A rain gauge measures the amount of rainfall at a location.

The simplest gauges collect rain in a container and measure the depth of water, usually in millimetres. A standard manual gauge uses a funnel and a calibrated tube, while automated tipping-bucket gauges record rainfall electronically by counting small bucket tips.

Rain gauges must be installed carefully. Buildings, trees, and uneven terrain can block or redirect raindrops, so meteorological stations place gauges in open areas. Snow may also be melted before its water equivalent is measured. A rain gauge records precipitation reaching the instrument, not the total amount falling across an entire region.