The climates in California’s winegrowing regions are diverse. They range from just barely warm enough to ripen grapes to so hot that the vines are in danger of withering.
At the same time, there is a common climatic influence in many of the areas – exposure to the Pacific Ocean. Thanks to cold waters sweeping down from Alaska, chilly air temperatures are the summertime norm along the Pacific coast.
It's a different story in the huge valley running down the middle of the state. Far from the cooling ocean, the Central Valley turns into a furnace under California's baking sun. As superheated air rises high above the valley floor,...