Rainfall refers to the amount of precipitation that falls to the ground over a given period. It is one of the most important weather measurements used to understand climate, water supply, and storm intensity.
Rainfall is measured using a rain gauge. The measurement represents how deep the water would be if it accumulated on a flat surface without evaporation or runoff.
For example:
Used worldwide and standard in meteorology.
Commonly used in the United States.
Rainfall intensity describes how fast rain is falling. It is usually measured in mm per hour.
Rainfall affects agriculture, water supply, flooding risk, and daily weather conditions. Understanding rainfall helps interpret forecasts and prepare for changing conditions.