In order to do a good job in rainstorm analysis and service, the meteorological department generally stipulates that the precipitation reached within 24 hours is called rainstorm.

Heavy rain occurs when the rainfall exceeds 50 mm in 24 hours.

In the weather forecast issued by the meteorological department, professional terms such as light rain, moderate rain and heavy rain are different:

Light rain means that the precipitation within 24 hours does not exceed 10 mm,

Small to moderate rain 5 mm ~ 16.9 mm,

Moderate rain10mm ~ 24.9mm,

Moderate to heavy rain 17mm ~ 37.9mm,

The rainstorm is 25 mm to 49.9 mm,

The rainstorm is 38 mm ~74.9 mm.

If the rainfall exceeds 50 mm in 24 hours, it is called rainstorm.

More than 100 mm is called rainstorm.

More than 250 mm is called a torrential rain.