Dense fog is common during the late spring and early summer months, but may occur at any time. Ocean water temperatures range from the lower 50s (°F) in the winter to the upper 60s in the fall. Due to this weather variation, visitors to the islands should dress in layers, with short and long pants, fleece jacket or sweatshirt, windbreaker, hat, sunscreen, and waterproof outer clothing. In addition, visitors should wear sturdy hiking shoes with non-slip soles.