Historian Kevin Starr, in his Americans and the California
Dream (1973), called the state "an American Mediterranean." The
description is apt for much of coastal California and parts of the
interior valleys that enjoy a Mediterranean climate with relatively
warm, dry summers and mild winters.
Even within this zone, however,
are important regional variations. Along the coast, marine air
and fog keep temperatures more moderate
than in the Central Valley where summers are generally hot and
cloudless. An intermediate version of the Mediterranean climate is
found in
the Coast Ranges and the foothills of the Sierra Nevada.