The climate of the Redwood Creek basin varies from moderate seasons along the coast to the more extreme seasons common to the higher inland areas. The predominant influence on the climate in the lower basin, extending some ten to twenty miles inland, is moist marine air, which moves inland by prevailing onshore winds. Fog is a dominant climatic feature along the coast, generally occurring daily in the summer and not infrequently throughout the year. This oceanic influence has a greatly moderates the climate of the coastal areas over most of the year. Temperatures in the coastal region of the Redwood Creek basin vary only slightly, with a seasonal difference of only 10–15°F. For example, mean temperatures at Redwood Park are 47°F in January and 59°F in June.