German Wine Route: Climate
Wine growing does not only depend on the spacious macro climate, it is also influenced by the meso climate and the even smaller area conflicting micro climate.
Vine is cultivated when the mean temperature in july is beyond 18° C. Other wine growing regions in Germany depend on exposed southern slopes to engage in wine growing. The german word for vineyard is "Weinberg" what literally means "Wine mountain" what is emphasized for example in the cliffy vineyards in the Moselle region whereas vineyards in the Palatinate (Pfalz) wine growing region are in relative flat terrain.
The warm climate on the German Wine Route is so comprehensive that wine growing is possible from the eastern end of the Palatinate Forest to the outskirts of the lower hill zone where the vineyards just overtop the cold air masses that are accumulated in the lower lying rhine rift.
Especially fundamental climatic terms for wine growing are:
- Maximum potential for radiative heat transfer (Sunshine duration, over clouding, gradient of the slope, exposition)
- Minimal detraction of wind (stable air masses)
- Minimal detraction of cold air (Protection against affluxion of cold air, unhindered outflow of cold air, altitude overtopping areas where cold air accumulates)
The climatic advantages of the Palatinate wine growing area are:
- Position inside the rhine rift beneath the protecting Palatinate Forest
- Specific terrain shape inside the lower hill zone on elevations above cold air mass accumulation areas
Significant is also the low altitude of 100 - 300m on the edge of a low mountain range. Like other landscapes in river valleys; for example Moselle, Main and Neckar the warming out speeds the neighbouring regions, especially in summer. The mean temperature in july in a small area from Landau to Gruenstadt is beyond 19° C.
Prevailing winds from western and south western directions overflow the over 600m high Palatinate Forest and force air masses to ascend on the east and descend on the west. Although the altitude difference is just about 400 meters, down slope winds in lee (downwind side) result in warm foehn winds.
Over clouding over the Palatinate Forest in the west and the rhine rift in the east whilst cloudless sky on the Palatinate wine growing region area is a not an uncommon sight due to these foehn winds.
Across the German Wine Route is a small zone of less cloud over in long time average what leads to a longer sunshine duration, resulting in a lower number of cloudy days and in turn to less days with precipitation. As a result the whole area inside the rhine rift has the lowest precipitation rates and longest sunshine duration of Germany. The effection of these winds are lesser distinct on the Southern(most) Wine Route due to slightly lower mountains in the Wasgau and Vosges area. Whilst the northern part of the wine Road, the central Haardt, has an annual rainfall of about 500mm, the area more in the south comes up to 700mm.