The Santa Cruz Mountains is a cool, wet grape growing region with temperatures moderated by the marine influences of the Pacific Ocean. The majority of the annual precipitation falls between November and April averging 30 inches annually along the coast, with almost twice that in the mountains. Average high temperatures range from 70 to 76 degrees from May through October. Heavy summer fogs frequently cover the ocean-facing slopes and valleys, resulting in drizzle which sustains the moisture-loving redwood forests. Winter temperatures range from the upper thirties to the middle fifties with valley frosts common. Santa Clara Valley is warmer and dryer. Mountians shield the summer fog and much of the marine influences. Average high temperature is 84 degrees in July, with average rainfall of only 15 inches.