World Wine Regions – North America – California

Even though wineries exist in every American state, California continues to produce approximately ninety percent of all American wines (of all types, styles, and price ranges). This statistic is somewhat misleading, however, because California is big, and comprises a number of diverse wine producing regions, counties and AVAs. California effectively operates as if it were four different wine states


  • the hot climate agricultural powerhouse Central Valley
  • the Central Coast: the coastal areas between Santa Barbara and San Francisco Bay
  • the Northern Coast: Napa, Sonoma, Mendocino, Lake counties and adjacent areas
  • the cooler inland Sacramento-San Joaquin River Delta and the Sierra Foothills


Most of California is ideal wine country. It has a dependable growing season with ample sunshine. It seldom rains at harvest time. Pacific Ocean influence supports significant cool-climate regions. It has a wide variety of soils, climates, hills and valleys for vineyard placement.


California has two major problems as a wine producing region: labor availability and drought.



In southern California, the South Coast AVA includes the counties of Los Angeles, San Diego, Riverside, Orange and San Bernardino. Tucked away among sprawling cities are some 3,000 acres of vineyards, much of it in the ocean-influenced Temecula Valley and San Pasqual Valley AVAs. For many years, production centered around Chardonnay, but Pierce’s disease had driven growers to diversify into hardier grapes like Syrah, Tempranillo and Sangiovese.

The Central Coast AVA is immense, stretching the 250 miles from Santa Barbara in the south to San Francisco in the north in a six-county swath about 25 miles wide, and encompassing over 90,000 acres of wine grapes. Wines may, of course, be labeled “Central Coast.”  Because the area is so extensive, the label term “Central Coast” means little, except perhaps the supposition that the wine was produced under cool climate conditions. It is more meaningful to cover the Central Coast on a county- by-county basis. The three southernmost counties are most important. The northern counties, which include many urban area and Silicon Valley (and hence have very expensive land), make less of a vinous imprint.


We will start in Santa Barbara County on the Central Coast and work our way north.



Santa Barbara County and its Santa Ynez Valley have an unusual west-to-east topographical configuration. Cooling Pacific breezes extend a full twenty miles inland. The average temperature rises one degree per mile as you travel eastward and inland. As a result, the Santa Rita Hills AVA specializes in cool climate Pinot Noir and Chardonnay. Further inland, Ballard Canyon produces warmer climate Syrah, and further inland still, Happy Canyon brings us excellent Cabernet Sauvignon. The Santa Maria Valley in the cool-climate north is best known for Pinot Noir, Pinot Blanc, Chardonnay and some Syrah. In Santa Barbara County you can take a side trip to the Lompoc Wine Ghetto, a grouping of drab industrial buildings that house over two dozen wineries and tasting rooms.


Diagram of the Lompoc Wine Ghetto



San Luis Obispo County is directly north up the coast. In the original Spanish, San Luis Obispo stands for “St. Louis, the Bishop”.


San Luis Obispo County has four primary wine regions. The Arroyo Grande Valley, Edna Valley and York Mountain AVAs are all within a few miles of the Pacific Ocean. Climate here is cool but remarkably steady, favoring Pinot Noir and Chardonnay, as well as aromatic white varietals like Pinot Gris, Riesling and Gewürztraminer. Soils are complex, often revealing fossils of ancient sea creatures, a quality that allows growers to plant varieties and clones that get the most from the county’s diversity.

Edna Valley, San Luis Obispo County, California. Photo by Elliot Essman


The fourth region is Paso Robles, which until a few years ago, at least politically, was one huge AVA stretching across the northeastern expanse of the county. Growers here lobbied the TTB to divide Paso Robles into no fewer than ten individual AVAs. They proved the impressive vinous diversity of the area and got their AVAs. The area has seen increased plantings of the Rhône varieties Syrah and Viognier, with the warmer mountainous eastern stretch becoming known for some fine Zinfandel, as well as Bordeaux varieties like Cabernet Sauvignon and Merlot. (Locals pronounce Paso Robles in an anglicized way, as Paso ROE-bulls, rather than the more Spanish-sounding Paso Robe-Lace.)


Next county up (but still considered Central Coast) is Monterey County.


The Salinas River flows about a hundred miles southeast to northwest, flanked by the Gabilan Range to the east and the Santa Lucia Range on the west, emptying into the Pacific at Monterey Bay. The valley floor, characterized by sandy loam and gravel, is a fertile agricultural area, renowned for all kinds of crops (well described in John Steinbeck’s novel, East of Eden), as well as a good deal of wine production. The limestone, granite and shale soil of the hills flanking the valley have seen increasing colonization by the vine. The Monterey AVA covers most but not all of the wine area, which includes eight smaller AVAs.


Underneath the Pacific Ocean facing into Monterey Bay and the Salinas Valley is an immense underwater canyon, larger than the Grand Canyon. The canyon generates cooling fog that funnels down the valley. The result, for the northernmost AVAs of the county, is a cool climate, but one with a long growing season, with long warm days to ripen the grapes, and cool nights to let them rest. The AVAs further south are hotter, but not beyond ocean influence.


Although fruit-forward Chardonnay and Pinot Noir account for much of Monterey wine production, growers are actively producing another forty varieties.


Central Coast—Further North


Between Monterey and San Francisco, the Central Coast AVA includes Alameda, Contra Costa and San Francisco counties, and parts of San Mateo, Santa Clara and Santa Cruz counties. This is excellent wine growing country, with well-drained gravel soils, warm days and cool nights because of the effect of the ocean and San Francisco Bay. The area has about six thousand acres of vines and one hundred wineries, but these must coexist with Silicon Valley and urban sprawl.

Well-known grapes like Chardonnay, Cabernet Sauvignon and Merlot account for a good half of production. This area includes the Santa Clara Valley, one of the state’s oldest wine regions, a narrow strip just south of the big city of San Jose. The growing human population of the region may menace the environment and hyper-inflate land values, but it brings a steady stream of day-tripping customers to the area’s wineries, allowing many of them to sell their wine at full retail.


Livermore Valley AVA


Livermore is situated in Alameda County, east of San Francisco Bay. Here, large operations Wente and Concannon coexist with many smaller producers. The valley has an east-west orientation and well-draining gravelly soil. Although breezes off San Francisco Bay assure good diurnal temperature differentials, Livermore is warmer than much of the ocean-influenced, Central Coast, with a climate suitable for  Bordeaux varieties like Cabernet Sauvignon and Merlot as well as Rhône varieties like Syrah and Viognier, with some Chardonnay and Sauvignon Blanc. Human population pressure is the greatest threat to Livermore’s vines.


Santa Cruz Mountains AVA


This AVA is not legally part of the broad Central Coast AVA, which it borders. It is south of San Francisco and west of Silicon Valley. On the eastern side of the region’s high ridges (up to 2600 feet), the warm climate produces Cabernet Sauvignon, Merlot, Zinfandel and Syrah. On the ocean side of the ridges, Pinot Noir is the leader. The AVA has about 60 wineries.


California Central Valley



Shown in yellow on our California wine map, the flat Central Valley stretches more than 450 miles southeast to northwest through the center of the state. The flat, largely irrigated valley is about 40 to 60 miles wide. It features some of the most productive agricultural land on the planet, producing more than half of the fruits, vegetables and nuts grown in the United States. This includes table grapes, raisins and bulk wine grapes, but the climate is too warm for fine wine production. Because of the hot climate, wine grapes with high natural acidity do best, including Chenin Blanc and Colombard. The Central Valley is not an AVA, meaning its wines can only be labeled under the broader “California” appellation.


The center of the valley is a climatic exception, however. Here the north-flowing San Joaquin River meets the south-flowing Sacramento River to form the Sacramento-San Joaquin River Delta, an extensive system of rivers, canal and marshes. This in turn drains into San Francisco Bay. The delta and the bay system tend to cool the middle of the valley, allowing quality wine grapes to grow in appellations such as Clarksburg (with 9000 acres of vines) and Lodi (with

ten times as much). As the map of Lodi’s seven AVAs clearly indicates, Lodi is well influenced by water systems. It also benefits from sandy clay soils that drain well. Lodi’s reputation leads with its fine Zinfandel (nearly half of Lodi production). It also produces Syrah, Cabernet Sauvignon, Merlot and white wines like Viognier, Sauvignon Blanc and Chardonnay.



Sierra Foothills

West of Lodi are the eight counties of the Sierra Foothills AVA. Although well inland, the climate is moderated by the area’s elevation and also by the cooling influence of the Sacramento-San Joaquin River Delta system. This is Gold Rush country. The miners of the mid-19th century were a thirsty bunch. By the 1860s, the foothills had a thriving wine industry, particularly associated with Zinfandel. The gold mania subsided, but the vines continued to grow, in many cases under the loving and expert care of Italian immigrant winemakers. This wine culture, and the toughness of the vine itself, got Zinfandel to the other side of Prohibition. The worst threat to Zinfandel came in the late twentieth century when a new mania—this time for Cabernet Sauvignon, saw Zin vines pulled up and vineyards repurposed. In the nick of time, the thirst for white Zinfandel (which is made from the red Zinfandel grape), allowed Zin to take its place as “California’s native grape.” The AVA’s hundred or so wineries produce Zin, often from old vines (which have no legal definition but are often many generations old), with lesser amounts of Cabernet Sauvignon, Syrah, and even smaller amounts of Chardonnay, Merlot, and Barbera.

Sierra Foothills has five sub-AVAs. The California Shenandoah Valley AVA, El Dorado AVA, Fair Play AVA, and Fiddletown AVA are bunched in the center of the region, in Amador and El Dorado Counties, and focus on Zinfandel. The North Yuba AVA in the northernmost county of Yuba is more removed form the cooling influence of the Delta and has a warmer climate suitable for Cabernet Sauvignon and the Rhône grapes Syrah, Grenache, Viognier and Roussanne.


North Coast AVA.

Six counties make up the North Coast AVA: Marin, Solano, Lake, Mendocino, Napa, and Sonoma. Wines sold under the “North Coast” label are usually blends of grapes from more than one of the counties.

Although Marin County just north of the City of San Francisco is highly affected by urban sprawl, the northern reaches of Marin have extensive agricultural lands that are legally protected from property development. While the entire north coast is known for cool-climate viticulture, Marin, sandwiched between the ocean and the bay, may be downright cold. The saving grace is a long growing season. Marin has about 200 acres of grapevines, divided among a handful of family growers, producing Pinot Noir, Chardonnay, Gewürztraminer, and Riesling.

Solano County lies between the eastern reaches of the bay/delta system and the state capital of Sacramento. Two of Solano’s AVAs are part of the North Coast AVA. The Solano County Green Valley AVA, just north of San Pablo Bay, produces Cabernet Sauvignon, Merlot, and Syrah on about 800 acres. The Suisun Valley AVA, further north, is one of the state’s oldest wine producing regions, producing a wide range of grapes on over 3,000 vineyard acres.

Lake County directly north of Napa, surrounds Clear Lake, California’s largest lake. Although the county is inland and removed from the influence of the bay and delta system, the lake itself combines with substantial vineyard elevations to prevent the climate from getting too hot. Lake County AVAs include the Clear Lake AVA, the High Valley AVA, and the Red Hills Lake County AVA. The county’s proximity to Napa makes it a prime purchasing source for winemakers from elsewhere, but it also has more than a dozen wineries of its own. Cabernet Sauvignon leads, with Sauvignon Blanc second.


In Mendocino County, on the Pacific Coast directly north of Sonoma, wine grapes are by far the most prominent legal agricultural product, covering 16,862 acres as of 2015: 4500 planted to Chardonnay, 2600 each to Pinot Noir and Cabernet Sauvignon, 1900 to Zinfandel, and 1400 to Merlot. Organic wine grapes account for a total of 3900 acres (and the county has been GMO free since 2004). Mendocino has ten AVAs.


The Anderson Valley AVA is making a reputation for itself in sparkling wines, led by French Champagne house Roederer. The northern end of the valley (one of California’s coolest regions) is closer to the Pacific Ocean than the warmer southern end. Anderson and the nearby Mendocino Ridge AVA produce Pinot Noir and Chardonnay for still and sparkling wines as well as Riesling and Gewürztraminer. A little further north, the Redwood Valley AVA is known for peppery Zinfandels, Potter Valley for Chardonnay, Pinot Noir and Sauvignon Blanc, Eagle Peak for Pinot Noir (from its single winery).

Further north still, the Covello and Dos Rios AVAs total only a few acres of vines between them, producing Cabernet Sauvignon, Cabernet Franc, Chardonnay, Merlot and Zinfandel in warmer inland climates than those appellations further south.

The Yorkville Highlands AVA is a continuation of the southeastward reaching Anderson Valley that at its southern end nudges the northern end of Sonoma’s Alexander Valley. Yorkville Highlands has rocky soil with high gravel content and good drainage. The daytime climate is cooler than Alexander Valley but warmer than Anderson Valley. At night these highlands get chillier than either of their neighbors.

South of Mendocino’s largest city Ukiah (which is not particularly large), the Cole Ranch AVA  is the smallest appellation in the United States (only one winery producing Cabernet Sauvignon, Merlot, Pinot Noir and Riesling). In the county’s southeastern corner, the McDowell Valley AVA makes Rhône wines from old-vine Syrah and Grenache. Some of these vines are more than 100 years old. McDowell is also known for dry rosés.

We have saved the two big players, Napa and Sonoma, for last. For starters, let us look at ways in which these neighbors are profoundly different form each other.

  • Sonoma is twice the size of Napa
  • Sonoma has four times the population of Napa
  • Sonoma has a large city, Santa Rosa (population 175,000), while Napa has no large cities.
  • Ocean-facing Sonoma has a cooler climate than inland Napa, although the southern reaches of both counties are also cooled by San Pablo Bay. Some of Sonoma’s ocean fogs do reach eastward across the center of the county to affect Napa.
  • Sonoma has a number of overlapping AVAs, while Napa’s AVAs do not overlap.
  • Sonoma produces agricultural products other than wine grapes (although grapes are number one), while Napa is all grape.
  • The Mayacamas Mountains physically and climatologically separate Sonoma and Napa. Only two widely separated east-west roads connect the two counties.