The Föhn
A Föhn is a weather phenomenon that influences the climate throughout Europe and in Switzerland makes it possible to grow grape varieties in regions that would otherwise be inhospitable.
The Föhn is a dry wind that blows down the leeward slopes of mountains. The word Föhn is a generic German term originally just applied to winds in the European Alps, but Föhn is now used for all similar winds such as the Chinook in the U.S. Rockies.