A rain gauge measures precipitation collected over a known horizontal area. The reported rainfall depth is collected liquid volume divided by collector area: . A tipping-bucket gauge converts repeated fixed-volume tips into accumulated depth; a weighing gauge measures collected mass.
Wind can deflect drops around the opening, and evaporation, splashing or freezing can bias the result. A gauge samples one location, so its reading need not represent a whole catchment during spatially uneven rain. The instrument geometry and exposure are therefore part of interpreting the observation.
Articles by others on the same topic
A rain gauge is a meteorological instrument used to measure the amount of rainfall over a specific period of time. It typically consists of a narrow cylindrical container with a funnel at the top that directs rainwater into the container. The amount of rain collected is measured in millimeters or inches, and readings can be taken at various intervals to monitor precipitation levels.