A few broad valleys extend inland through the mountains. Virgin redwood forest on Mill Creek, near Crescent City, California. The annual temperature cycle is very weak, reflecting the powerful influence of the cold California sea current with its cool marine air layer. Cool summers are typical, and winter temperatures are much milder than those of inland locations at similar latitudes.
All months are above freezing.
Rainfall drops to nearly zero for 2 consecutive summer months, but rises to substantial amounts in the rainy winter season. Heavy fogs are common along the coast in summer. This region has a greater mean number of days with dense fogs than any other place in the United States. Associated with it are Douglas-fir and other conifers such as hemlock and cedar. The redwood forest is a hygrophyllic type of warm-temperate forest.