Cool Evenings, Warm Mornings
This distinct pattern of cooling during the warm growing season causes afternoons and evenings to be cool, even chilly, on Spring Mountain. As this cool air settles to the valley floor, and as the onshore flow subsides, warm air is lifted up and the temperatures rise towards morning. Often the vineyards on Spring Mountain face a clear dawn as the vineyards below on the valley floor lie in a blanket of fog.
Spring Mountain is a wet region. Though the summers and harvest are dry, the area gets more rainfall during the winter rain season. Eastward moving storms are pushed up as they pass over the ridge. As they rise into the colder air above the ridge, they drop rainfall on the lee side of the ridge. The lee side of the ridge is Spring Mountain.
Not only does it get more rain in the winter, but the district is shielded from the hot afternoon sun that radiates from the west. Protected from these hot conditions in the late afternoon, plants that are sensitive to drought will flourish.