In meteorology common name for water that is either in liquid form from rain or thunderstorm and / or in solid form of hail, Sleet, drizzle or snow from clouds falling to the ground, or surface precipitation directly by condensation (as in the case of dew ) or resublimation, that is to say immediate transfer of a substance from the gaseous to the solid state of matter (as in the case of ripening) to objects such as the earth's surface. The required rainfall in viticulture is also dependent on the soil conditions such as the water discharge and Water storage capacity dependent. The annual lower limit is at least 200 mm of precipitation, for quality wine growing average 500 mm, in warmer climates with high evaporation 750 mm required.
Under the condition of appropriate soil conditions there is no upper limit, because even more than 1,500 mm within a short time can be coped with, especially in hot areas. But the time of precipitation can be critical growth cycle his. A heavy rain just before the vintage Especially after prolonged drought, the grapes can swell and increase the content sugar. acids and flavorings dilute. An artificial one irrigation is regulated within the EU differently in national responsibility mostly by wine law. The rainfall is one of the criteria for the so-called Weinbauwürdigkeit,