The eastern boundary current of the North Pacific subtropical gyre. It flows southward along the coast of Washington and California and is associated with coastal upwelling during spring and summer (April–September). The associated low sea surface temperatures (about 15°C) produce a coastal strip of sea fog along the otherwise extremely hot coastline. In autumn and winter (October–March) the upwelling is replaced by northward flow known as the Davidson Current, which reaches its peak speed of 0. 2–0. 3 m s−1 in January.