District #1, The Central Valley Region, includes more than half the acres of California’s citrus production. This
region has summers that are hot and dry and winters that are typically cold and wet. Almost all of the
state’s navel orange production is grown in this region though Valencia orange production is also
significant along with lemon and grapefruit production. Over half of the state’s tangerines are grown in
the Central Valley region.
District #2, The Coastal Region, from Santa Barbara County south to Riverside and San Bernadino counties,
has a milder climate influenced by marine air. This region is the major producer of lemons.
Valencias are the primary orange variety produced in this region.
The Coastal Region also includes inland portions of Orange and Los Angeles Counties and other growing regions that are only marginally affected
by coastal climatic influence, in contrast to the coastal district, which is significantly
influenced by the moderating influence of the coastal climate. The desert district tends to be warmer
and dryer in the summer and colder in the winter than the coast.
District #3, The Desert Region, primarily the Coachella Valley and Imperial Valley with portions of San Diego county, produce citrus under conditions
where temperatures fluctuate widely between day and night with low humidity most of the year. The
desert region is the primary location for production of grapefruit. A good amount of the state’s lemons are produced here.