⦗🧛⦘ ⦓☾✹✯𝚅𝚒𝚎𝚕𝚕𝚎✯✹☽⦔ (viellain)

Valley (or graben) breezes and mountain breezes are a very localized phenomenon. They relate directly to daily temperature variations between summits and bases. Since it is in the highest reaches that the maximum diurnal range is attained, it is the summits which drive the mechanism. Nights in the mountains are colder than those in the valleys below, especially if moist air collects in those valleys.