St. Helena is in the heart of the Napa Valley, nestled between Calistoga to the north and Rutherford on its southern border. On its western side, the Mayacamas Mountains guard it from the cooling effects of the Pacific Ocean; to its east stand the Vaca Mountains. In conjunction, these mountain ranges serve to lock in summer daytime heat. But in the evening, cool air from the San Pablo Bay funnels up through the valley, creating very chilly nights. It isn’t uncommon for temperatures to drop 50 degrees, a shift that promotes a balance of sugar ripeness and acidity in wine grapes.
St. Helena contains a plethora of different soil types in a small area, which have been enhanced over centuries by rain runoff from both mountain ranges. Its vineyards cover a variety of terrain, spreading across the bucolic valley floor and its benchlands.
