Term for the totality of all meteorological processes or possible weather conditions, including the typical sequence as well as the diurnal and seasonal fluctuations, which are responsible for the average condition of the earth's atmosphere at a specific location. The name (Greek climate = curvature) is derived from the curvature of the earth's sphere and the resulting local differences in the angle of incidence of the sun. The climate is not only influenced by processes within the atmosphere, but rather by the interplay of all spheres of the earth (continents, oceans, atmosphere) as well as solar activity. Climate is one of the most important factors influencing viticulture.
As a distinction to the weather (hours to weeks) and to the weather (some days to a week, up to also a month or a season) one understands climate as a statistically determined condition of the earth's atmosphere over the period of several decades (at least 30 years). Areas of similar climatic conditions are classified into climatic zones. There are various classifications; the best-known originates from the German-Russian climatologist and biologist Wladimir Peter Köppen (1846-1940). This was then continued by the meteorologist Rudolf Geiger (1894-1981).
The climate characteristics result from many factors such as exposure (solar radiation), precipitation, temperature, humidity and wind as well as their sequence and interaction. Besides the soil type, the grape variety planted there and the individual way of vinification, the climate is a decisive factor for the wine quality. However, the very specific climatic conditions for a small area in which the vineyard is located (microclimate, Lageklima) and even smaller-scale conditions (microclimate) also play an important role. The vine thrives best in warm, temperate zones of the northern and southern hemispheres, the so-called vine belts. These are the relatively narrow areas between 40 and 50 degrees latitude in the northern hemisphere and between 30 and 40 degrees latitude in the southern hemisphere.
The grapevine needs above all warmth and light. According to studies by the Geisenheim Research Institute, the optimum temperature for growth is between 25 and 28 °Celsius. This is mainly determined by the altitude. As a rule of thumb, it drops by 0.6 °Celsius for every 100 metres difference in altitude. A hillside location is ideal in terms of vertical solar radiation. In addition, the thermals are favourable, because the cold air currents fall down the slope at night, where they warm up in the morning and move back up again during the day. This cycle is especially important for quality white wines in terms of acidity. The tops of hills are planted with trees in order to slow down the influx of cold air, which is mainly used in Europe in the countries of Germany, Austria and France. Waters (rivers, lakes, seas) have a positive climatic influence on viticulture because they reflect light. It is therefore no coincidence that many important wine-growing areas worldwide are located along bodies of water.
The northernmost vineyards for quality wine cultivation are located in Germany (51st parallel) and England (52nd parallel). The southernmost wine-growing borders are at the Cape in South Africa (35th parallel), in Argentina and Chile, and on the southern main island of New Zealand (40th parallel). From the equator to 20 degrees north and south latitude there is no viticulture due to tropical conditions of heat and drought, or only in higher areas up to 2,000 metres above sea level such as Kenya. Outside these areas there is too little sunlight and precipitation or the danger of cold and frost. The suitability of a region for quality viticulture is described under viticulture suitability.
The first scientific study concerning the influence of Kima on viticulture was made by the Swiss botanist Augustin Pyrame de Candolle (1806-1893) in the middle of the 19th century. These findings were used by the two US researchers Albert Julius Winkler (1894-1989) Maynard A. Amerine (1911-1998) from the University of California. In 1944, they introduced the so-called heat-day summation system (degree-days), which divides California into a total of five climate zones. In the meantime, a number of different...