bergwind

Bergwind is a meteorological term used to describe a warm, dry wind that descends from mountainous terrain toward lower-lying areas or along coastal plains. The word combines the German berg meaning "mountain" with wind, and the term is used in various regions, including German-speaking parts of Europe and in Afrikaans-speaking South Africa.

Bergwinds typically develop when air over mountains is heated by daytime solar radiation and rises on the windward side. As air descends on the leeward side, it compresses and warms, reducing humidity. The resulting downslope flow is usually dry, gusty, and associated with clear skies and rapid temperature rises in the valleys or lowlands.

Regional variants include the Alpine or European bergwind, common on sunny afternoons in certain valleys, and the South African bergwind, which can spread from the interior plateau to the coast. The South African version is often linked to a strong inland high pressure that drives air over the escarpment and toward the sea, producing hot, dry conditions and sometimes dust.

Impacts of bergwinds include higher daytime temperatures, lower humidity, and increased risk of wildfires in vegetation-rich areas. They can affect agriculture, energy demand, and outdoor activities, and are an important factor in regional weather forecasting and aviation in affected regions.

Bergwind is related to other downslope wind phenomena such as the Föhn or Chinook, which share the downslope warming mechanism though they occur in different geographic settings.