ScienceDaily (Dec. 13, 2010) — Fog is a common feature along the West Coast during the summer, but a University of Washington scientist has found that summertime coastal fog has declined since 1950 while coastal temperatures have increased slightly. Fog formation appears to be controlled by a high-pressure system normally present off the West Coast throughout the summer, said James Johnstone, a postdoctoral researcher with the Joint Institute for the Study of the Atmosphere and Ocean at the UW. "The behavior of that high-pressure cell is responsible for a lot of the weather phenomena we see on the coast," he said. It can alter water temperature, ocean circulation, surface winds and other factors linked to coastal fog formation.
http://www.sciencedaily.com/releases/2010/12/101213121743.htm