Light rain, moderate rain and heavy rain standard

The standards for light rain, moderate rain and heavy rain are as follows:

The daily rainfall below 10 mm is light rain; Daily rainfall 10-24.9 mm is moderate rain; The rainfall of 25-49.9 mm is heavy rain.

Rainfall refers to the depth at which liquid or solid (after melting) water falls from the sky to the ground and accumulates on the horizontal plane without evaporation, infiltration and loss.

Precipitation is in millimeters, and meteorological observation takes one decimal place, which can directly indicate the magnitude of rainfall. Generally speaking, light rain, moderate rain, heavy rain and rainstorm are generally measured by daily rainfall.

Among them, light rain means that the daily rainfall is below 10 mm; Daily rainfall in moderate rain10-24.9mm; The rainstorm rainfall is 25-49.9 mm; The rainstorm rainfall is 50-99.9 mm; The rainstorm rainfall is100-250mm; The rainstorm rainfall is above 250 mm.

Rainfall is usually measured by a rainfall pipe, so it may contain a small amount of dew, frost and frost. Meteorology, there are often years, months, days, 12 hours, 6 hours or even 1 hour of precipitation. All the rain and snow falling within 6 hours melt into water, which is called 6-hour precipitation.

All the rain and snow falling within 24 hours melt into water, which is called 24-hour precipitation; A ten-day rain and snow melt into water, which is called ten-day precipitation ... In a year, all the rain and snow melt into water, which is called "annual precipitation".

Liquid precipitation is called rainfall, and sometimes the two are synonymous. The precipitation per unit time is called precipitation intensity, usually in millimeters per hour or millimeters per minute. The rainfall per unit time is called rainfall intensity. The average annual rainfall of a place for many years is called the "average annual rainfall" of this place.

For example, the average annual rainfall in Beijing is 532.0mm, and that in Shanghai is 1 166. 1mm ... Precipitation refers to a weather phenomenon in which liquid water or solid water falls to the ground. Accurate measurement of precipitation is of great significance for weather forecast, climate analysis, monitoring and early warning of natural disasters such as floods, landslides and mudslides.