Tillamook is particularly affected by these yearly floods, because of its location on a major floodplain. Sandstone cliffs occur rather sporadically in this region. This is due to relatively slow uplift rates as well as fairly constant sediment wash from the Columbia River. Future uplift from the subduction of the Juan de Fuca plate will eventually create sandstone cliffs similar to those found further south and north. The North Oregon Coast is also a part of the Graveyard of the Pacific. The weather on the North Coast is moderate. The average low in the winter is just under , while the high temperature is just above . The average high reaches its peak in early September at . The most rain occurs in November and December averaging over each month. July and August are the driest averaging under of rain each month. Most days are cloudy or partly cloudy throughout the year. The summer has the most sun with approximately half the days sunny or partly cloudy. The Central Coast, which extends from Cascade Head to Reedsport, while similar to the North Coast, possesses fewer sandy beaches, more sea cliffs and terraces, and a greater number of bays. Several small urban areas exist in this region. Among these are the cities of Lincoln City, Depoe Bay, Newport, Waldport, and Yachats. Because the usable lands of the region are squeezed between the mountains and the ocean, most urban areas are relatively small but are still larger than those of the South Coast region. The southernmost area of Central coast is the intermediary zone for this region and the more mountainous South Coast region. Exposed sandstone cliffs are also common along the beaches and highway. Local sandstones of the Central Coast were uplifted during the Neogene Era. Higher layers of exposed sandstone are often varying shades of orange, and are often quite soft to the touch, often being very brittle, and relatively easily eroded. Lower exposed layers, though less frequent, reveal harder sandstone deposits. Unlike the higher layers, they are often gray-brown in color and hard in comparison. This lower sandstone often breaks off in large, squared chunks. The weather on the central coast is similar to that of the north coast except the frequency of sunny or partly cloudy days is higher in the summer, approaching 75%. The South Coast region, which extends from Reedsport to the California border, is distinct from the North and Central Coast regions because of its mountainous nature, due to tectonic uplift and terrane accretion in ancient times. Much of the coastline in this region is made up of sea cliffs and miles of beaches.