Precipitation – Concept, water cycle and how it is measured

We explain what precipitation is in meteorology, its participation in the water cycle and what is the point of greatest rainfall on the planet.

Rainfall is of vital importance to sustain the biosphere.

What is precipitation?

In meteorology and other similar disciplines, the term precipitation is used to refer to the fall of any physical manifestation of water from the lower layers of the atmosphere to the earth’s surface, such as rain, drizzle, snow or hail. The term comes from the verb precipitate, which according to the dictionary means “to throw something or someone from above.”

Precipitation is a natural and crucial part of the hydrological cycle, and occurs due to the accumulation of water vapor in clouds, the result of daily evaporation, until reaching a saturation point in which the water droplets increase in mass and are finally attracted by gravity.

The fall of rainwater is of vital importance for the support of the biosphere, as it balances the global climate and sustains plant life, in addition to moving important sediments from the highest to the lowest regions of the earth’s surface.

Although it can refer to any of the phenomena listed above, most of the time when talking about precipitation we simply refer to rain, in its different intensity variants. Not so to the mist, dew or the virga, which are meteorological phenomena resulting from the condensation of water vapor, and not from the precipitation of the latter.

The amount of precipitation that falls at a specific point on the earth’s surface is known as rainfall (or rainfall amount), and it is normally measured through rain gauges and rain gauges, located at strategic meteorological stations. These figures tend to vary throughout the year according to cycles determined by the rotation and movement of the earth, as well as the geographical characteristics of the region.

The point of greatest rainfall on the planet is Puerto López, in Colombia, with an annual margin of 892 millimeters of precipitation. On the contrary, the place where it rains the least in the world is the frozen desert of the Antarctic plateau, where low temperatures prevent the concentration of liquid water in the atmosphere necessary for the hydrological cycle.