Diurnal shifts - cool mornings, followed by warm sunny days and then cool nights allow grapes to ripen while enjoying a cooling down at night and in the morning to retain acidity and primary fruit aromas and flavors. The topography of notable wine regions in the state have a combination of valleys, sloped elevation and mountain ranges that provide ideal growing conditions that tolerate swings in temperature.

Relatively dry weather patterns with over 300 days of sunshine and limited rainfall - unlike most vegetation, grapevines do not like too much water. In fact, many varietals suffer when they have access to a plentiful water supply. Grapevines like to absorb water at key stages in the growing cycle (bud break through to flowering and again after veraison), but continuous access to water encourages heavy leaf and vine growth and dilution of sugars in the grape. In the atmosphere, too much rain during the summer and fall months prior to harvest can expose grapes to fungal diseases and rot. Dry sunny weather with limited rain provides ideal grape growing weather conditions to limit water access.

A long continuous coast with notable topography that creates unique coastal/marine influences to growing conditions - Ocean air is typically quite cool, and when it meets up with warm temperatures, fog develops. When burned off midday, fog acts as a cooling, acid pumping blanket to grapevines. Think of it as a nice break to regroup from ripening to develop fresh aromas and flavors, controlling sugar levels in the grape from getting to high (which can lead to overpowering flavors and high ABV levels during fermentation). Cool air from the Pacific Ocean is pulled into Sonoma via the Petaluma Gap, Carneros via the San Pablo Bay, into Monterey via the Blue Canyon, and transversely between mountain ranges in Santa Barbara. Cooler temperatures also allow for an expansion of varietals that can thrive in California; without these cooling influences, Chardonnay and Pinot Noir would struggle to grow successfully. Converse to marine influences, there are wine growing regions of California that have lengthy mountain ranges that serve as a shield to humid coastal air and fog. Because of the diurnal shift, cooler climate grapes can thrive in these regions, but do produce richer bodied wines, lower in acid with spice and non-fruit characteristics.

Origin of grape variety(s): If a specific AVA is listed on a label, a minimum of 85% of the grapes used must come from the stated appellation. If a label lists a county, state, or other country, the minimum is 75%. However, California, Washington, and Oregon are exceptions: Wines labeled with California or Oregon as the appellation must be produced entirely from grapes grown in these respective states.

Minimum grape variety percentage: If a county, state, or country is listed as the appellation, 75% of the grapes used to produce the wine must come from the stated appellation. If “U.S. Wine” or “American Wine” is listed on the label, a minimum of 75% of the grapes used to produce the wine must come from within the U.S. and the wine must be made in this country. Otherwise, if a more specific AVA is listed, 85% of the grapes must come from the stated appellation. If a single vineyard is listed on the label, 95% of the grapes must come from that vineyard.

Vintage laws: All vintage-dated wines, regardless of origin, must list a smaller appellation than a country. If a vintage-dated wine lists a specific AVA, 95% of the grapes must come from the stated year. For wines labeled with a state or county, the minimum is 85%.

Varietal laws: All wines listing a varietal designation must be made from a minimum of 75% of the stated grape variety. However, wines made from a Vitis labrusca grape, such as Concord, only have to be made from a minimum of 51% of the stated grape. Finally, if a wine is to be sold on the international market it must be made from a minimum of 85% of the stated variety.

Alcohol content laws: The alcohol content must be stated on the label. A leeway of plus- or minus-1.5% is allowed. Wines with an alcohol content between seven and 14% have the option of listing “table wine” or “light wine.”

Health and sulfites warnings: Every bottle of wine must list a government health warning, as well as “Contains Sulfites,” if the wine contains more than 10 parts per million sulfites.

Producer address and name information: Every bottle of wine must list the name and address of the bottler.

Estate Bottled: If a wine is labeled as “Estate Bottled,” it must be produced entirely from grapes either grown on land owned or controlled by the winery. The winery and all vineyards used in the production of an estate-bottled wine must also be located within the same AVA.

Grown, produced and bottled by: Similar to estate bottled. Here the winery grew the grapes on vineyards it either owns or leases with control over the farming.

Estate Grown: The winery and its vineyards are within an established AVA.

Produced and Bottled by: A minimum of 75% of the wine in the bottle must be made by the producer listed.

Made and Bottled by: A minimum of 10% of the wine is made by the winery or company listed.

Produced and Bottled by: At least 75% of the grapes were fermented in the winery’s facility. Some purchased wine can legally be blended in.

Vinted by or Cellared by: These two terms indicate that the finished wine was purchased in bulk and then given some sort of cellar treatment before bottling.

Reserve: Used to denote a winery’s best wine, typically made in limited quantities. However, there are no legal requirements pertaining to the term’s usage.

Limited Reserve: Another term often used on wine labels to denote a limited or best selection. Again, there are no legal requirements for using the term in the U.S.

Old Vines: A label designation signifying the wine was made from an older vineyard source. Like the previous two terms, there are no legal requirements for using the term. However, in regards to Zinfandel, it’s understood that the phrase “Old Vines” is used for wines made from vineyards older than 50 years.

Organic: Wine made from organically grown grapes.

Varietals: Merlot, Chardonnay, Pinot Noir,Cabernet Sauvignon, Cabernet Franc, Syrah
Earned AVA Status In: 2003
Vineyard Acres: 700
Wineries: 17
Elevation: 400 - 1100 ft.
Website: Bennett Valley AVA

Bennett Valley is nudged between three mountain peaks, making it one of the smaller AVAs in the area. It is known for small, grower-operated wineries. The Valley benefits from the rare combination of clay-like, volcanic, rocky soil and moderately cool marine influences such as morning fog and ocean breezes, which allow for a long growing season.

Varietals: Chardonnay, Cabernet Sauvignon, Sauvignon Blanc, Cabernet Franc, Zinfandel
Earned AVA Status In: 1983
Vineyard Acres: 10,040
Wineries: 22
Elevation: 0 - 700 ft.
Website: Chalk Hill AVA

Chalk Hill differentiates itself from other parts of the greater Russian River Valley because of its white volcanic ash hillsides that offer excellent drainage and sunny exposures. While being comparable in weather patterns, Chalk Hill is somewhat warmer, with light breezes and less cool fog and temperatures. It’s known for its mineral-driven white wines.

Varietals: Pinot Noir, Chardonnay
Earned AVA Status In: 2012
Vineyard Acres: 555
Wineries: 5
Elevation: 920 - 1200 ft.
Website: Fort Ross-Seaview AVA

The Fort Ross-Seaview AVA is located in the heart of the Sonoma Coast AVA. One of the closest appellations to the Pacific Ocean, the region is defined by its narrow valleys and mountainous terrain, where vines soar above the fog line on steep ridges. Despite the challenges of growing grapes here, the coastal conditions and diverse soils prove ideal for growing exceptional Chardonnay and Pinot Noir.

Varietals: Pinot Noir, Chardonnay
Earned AVA Status In: 1983
Vineyard Acres: 3600
Wineries: 10
Elevation: 100 - 800 ft.
Website: Green Valley AVA

Green Valley is in the southwestern part of the Russian River Valley, but it's slightly cooler and foggy with sandy, fast-draining soils. It’s very tightly delineated, both geographically and climatically, and is the most consistent of any North Coast appellation in terms of soil, climate and flavor.

Varietals: Cabernet Sauvignon, Zinfandel, Syrah, and Merlot.
Earned AVA Status In: 2013
Vineyard Acres: 1,500
Wineries: 4
Elevation: 400 - 2200+ ft.
Website: Moon Mountain District AVA

Located on the hills above the city of Sonoma, vines grow in a variety of soils, mainly rocky and of volcanic origin. Elevation is a key defining factor of this AVA, where hillside vineyards soar between 400 and 2,200 feet in elevation. The mountainous conditions and constant breezes prove favorable for growing structured Cabernet Sauvignon.

Varietals: Pinot Noir, Chardonnay, Syrah
Earned AVA Status In: 2017
Vineyard Acres: 4,000
Wineries: 9
Elevation: Below 1000 ft.
Website: Petaluma Gap AVA

This area is noted for afternoon wind and fog that comes from Bodega Bay on the coast and passes through the hilly areas and into San Pablo Bay. As inland valley air heats up, it pulls the cool coastal air into a naturally formed 15-mile-wide “gap” in the coastal range mountains. The soil is a combination of clay loam and sandy loam mixed with gravel. Daily temperatures can swing forty to fifty degrees. Vineyard yields are smaller and grapes ripen later, developing wonderful flavors and fruit characteristics while maintaining ideal levels of acidity. About 75% of the region is dedicated to cool-climate darling Pinot Noir.

Varietals: Zinfandel, Cabernet Sauvignon, Petite Sirah, Merlot, Syrah
Earned AVA Status In: 2002
Vineyard Acres: 192
Wineries: 0
Elevation: 800 - 2100 ft.
Website: Rockpile AVA

This dramatic, rugged AVA on the west of Lake Sonoma is known for its red varieties, such as Zinfandel. The terroir here is heavily influenced by the high elevation (roughly 1,900 feet), where rocky soils, steep hillsides, and long days with plenty of sun exposure allow the grapes to develop more concentrated, rich flavors.

Map link: Sonoma Coast
Varietals: Chardonnay, Pinot Noir, Syrah
Earned AVA Status In: 1987
Vineyard Acres: 4,725
Wineries: 7
Elevation: 400 - 1800 ft.
Website:Sonoma Coast AVA

The Sonoma Coast AVA expands a good portion of the county, stretching from San Pablo Bay to the border of Mendocino County. The AVA is known for its heavy rains and cool climate. Not far from the Pacific, there is more than twice the annual rainfall of its inland neighbors but can still be warm enough to ripen wine grapes because most vineyards are above the fog line.

Varietals: Chardonnay, Cabernet Sauvignon, Zinfandel
Earned AVA Status In: 1981
Vineyard Acres: 5,565
Wineries: 100+
Elevation: 400-2200 ft.
Website: Sonoma Valley AVA

This AVA centers on the Sonoma Valley in the southern part of the county. It’s bordered by the Mayacamas Mountains to the east and the Sonoma Mountains to the west. Winegrowers take advantage of a climate warmed by slanting rays of sun and cooled airflows from both the Petaluma gap (to the west) and the Santa Rosa Plain (to the northwest) to produce a wide range of wines with distinctive varietal characteristics.

It is known for its unique terroir, with Sonoma Mountain protecting the area from the wet and cool influence of the nearby Pacific Ocean. The cool air that does affect the region comes north from the Los Carneros region and south from the Santa Rosa Plain.

Because the valley is cooled from the north and south, it is different from other California north-south-oriented grape growing valleys in the interior. In the appellations of the North Coast, the wind is unique to Sonoma Valley and Carneros.

The soils of the Sonoma Valley, like the rest of the county are varied. One finds a wide disparity between valley floor and mountain soils; those found in flatter, valley areas tend to be quite fertile, loamy and have better water-retention while the soils at higher elevations are meager, rocky and well-drained. In general, the structure, rather than the composition of the soil, is the deciding factor where grape plantings are concerned.

Varietals: Bordeaux and Burgundian varietals
AVA Approval: 1983
Acres Planted: 300
Climate: Extensive coastal influence; hillside has moderate temperature swings.
Dominant Soils: San Andreas Fine Sandy Loam, Arroyo Seco Gravelly Sandy Loam
Min./Max. Elevations: 203 ft. / 2,762 ft.
Website: Carmel Valley AVA

Carmel Valley encompasses over 19,000 acres, with 300 acres of grapes under cultivation. Vineyards are located primarily within Carmel Valley and Cachagua Valley. Cachagua Valley’s unique mountainous terrain elevates grapes above the fog line, exposing them to a warmer climate, though temperatures vacillate.

These temperature swings elongate ripening time and growing season, which enacts a gradual maturation to generate greater fruit and wine complexity.

Varietals: Pinot Noir, Chardonnay, Syrah, Grenache
AVA Approval: 2022
Acres Planted: 436
Climate: Warm, high elevation reduces coastal influence.
Dominant Soils: Moderately coarse textured soils over a bedrock of granite, Sheridan-Cieneba-Auberry, high limestone content.
Min./Max. Elevations: 1,500 ft./2,370 ft.
Website: Gabilan Mountains AVA

The newest AVA shares land in Monterey County and some of San Benito County. Vineyard acreage in the Gabilan Mountains is relatively small, but the wines produced from these vineyards have minerality, complexity, and dense, pure fruit flavors. The quick-draining soils of the AVA stress the vines during the growing season, resulting in more intense flavors and rich, hardy skins less associated with vines grown in sub-optimally-drained soils. Additionally, well-drained soils are at less of a risk for root decay than waterlogged soils. The Gabilan Mountains AVA contains 6 commercially-producing vineyards covering a total of approximately 436 acres, as well as 4 wineries.

Varietals: Chardonnay. Northern section: Riesling and Pinot Noir. Southern section: Cabernet Sauvignon, Merlot, Syrah, Petite Sirah, and some Zinfandel.
AVA Approval: 1984
Acres Planted: 40,000
Climate: Cool to hot, based upon location within the 100-mile stretch of land.
Dominant Soils: Lockwood Shaly Loam, Chualar Loam, Placenta Sandy Loam, Rincon Clay Loam, Garey Sandy Loam
Min./Max. Elevations: 0 ft. / 2,320 ft.
Website: Monterey AVA

The Monterey AVA is the largest in the area, with over 40,000 acres, and extends the entire length of the county. Because it covers so much terrain, it has a diverse climate, which translates to exceptional grape diversity. Still, Chardonnay reigns supreme throughout the region, accounting for over 50% of vines in production.

Cooler weather, ocean breezes, and fog characterize the northern section, which produces cool-climate grapes like Riesling and Pinot Noir. In the South, it opens up to Salinas Valley, which can reach up to 100 degrees during the daytime. This warmer weather produces Bourdeaux varietals (Cabernet Sauvignon and Merlot), Rhone varietals (Syrah and Petite Sirah), and some Zinfandel.

Varietals: Over 20 varietals, including: Merlot, Syrah, Pinot Noir, Chardonnay, Sauvignon Blanc, Riesling
AVA Approval: 2004
Acres Planted: 5,000
Climate: Moderate, partially sheltered from breezes.
Dominant Soils: Garey Sandy Loam, Oceano Loamy Sand, Lockwood Shaly Loam
Min./Max. Elevations: 266 ft. / 1,670 ft.
Website: San Bernabe AVA

The most centrally located AVA in Monterey County, San Bernabe, consists of over 5,000 cultivated acres. San Bernabe has a variety of microclimates with temperatures varying 5 degrees Fahrenheit from end to end, resulting in some grape blocks ripening months before others within the same vineyard.

Temperatures are reminiscent of Napa Valley, but its variance of warm days and cool evenings often elongates the growing season by up to four weeks. Its unusual sandy Aeolian soil combined with modern irrigation techniques enables growers to adjust the vigor and quality of the fruit and produce rich, full-bodied wines with complex and mature aromas.

Varietals: Chardonnay, Pinot Noir, Syrah
AVA Approval: 1991
Acres Planted: 5,000
Climate: Cool, steady temperature climate.
Dominant Soils: Chualar Loam, Arroyo Seco Gravelly Sandy Loam
Min./Max. Elevations: 98 ft. / 2,349 ft.
Website: Santa Lucia Highlands AVA

The Santa Lucia Highlands AVA contains over 4,700 cultivated acres planted high up on southeast-facing terraces of the Santa Lucia Mountain range overlooking the Salinas River Valley. This AVA has a climate comparable to Burgundy.

This elevated position exposes vines to morning sunshine and afternoon maritime breezes. Ultimately, this climate results in a long growing season, enabling grapes to achieve maximum varietal potential.

Varietals: Syrah, Grenache, Viognier, and Roussanne
AVA Approval: 2013
Vineyard Acres: 550
Soil: Relatively uniform and predominantly clay limestone, clay loam and sandy soils.
Wineries: 9
Elevation: 560 ft - 1,165 ft
Website: Ballard Canyon AVA

The north-south oriented canyon accounts for only 10% of the Santa Ynez Valley AVA.

This orientation shelters the vineyards while providing a unique weather pattern of wind, fog, and maritime influence, Fogs flow in from the coast in the early hours of the morning before retreating in the afternoon. The vines in the south of Ballard Canyon are exposed to the fog for a longer period of time compared to those planted at higher elevations in the region's northern vineyards. Ballard Canyon has a mixed climate and experiences cold nights and short periods of day-time heat. It is typical to have daytime highs over 90°F and lows around 50°F during the growing season.

Varietals: Sauvignon Blanc, Cabernet Franc, Cabernet Sauvignon and Rhone varietals
AVA Approval: 2015
Vineyard Acres: 1,121
Soil: 95% of the area consists of Positas-Ballard-Santa Ynez soil. The Positas series consists of well-drained fine sandy loams that have a clay subsoil. The Ballard series consists of well-drained fine sandy loams and gravelly fine sandy loams formed in alluvium derived from acid shale and sandstone.
Wineries: 12
Elevation: 400 ft - 1000 ft
Website: Los Olivos District AVA

This AVA is entirely within the Santa Ynez Valley AVA. It’s a broad alluvial terrace between the Purisima Hills above Solvang and the western flank of Happy Canyon. Los Olivos has a consistency rarely found in Santa Barbara County and it is distinguished by its uniform topography, geology, and soil profile. The terrain slopes gently, with a moderate climate marked by warm days with occasional morning fog and cool nights. its open valley topography allows for more intrusion of coastal fog that moderates the large swings in day-night temperatures. This moderate diurnal temperature range is a key element in the area climate, allowing full physiological maturity to be reached at lower sugars.

Map link
Varietals: Chardonnay, Pinot Noir in the west. Cabernet, Merlot, Sauvignon Blanc in the east. Rhone varieties such as Syrah, Grenache, Mourvedre, Roussanne, and Viognier also thrive.
AVA Approval: 1983
Vineyard Acres: 7,500
Soil: Approximately 7 principal soil associations are found in AVA. They include limestone, fine, sandy loam, and a complex mixture of loam and clay loam with red and yellow chert and serpentine cobbles.
Wineries: 78
Elevation: 220 ft - 1430 ft
Website: Santa Ynez Valley AVA

The Santa Ynez Valley AVA contains four sub-AVAs: Sta. Rita Hills, Ballard Canyon, Los Olivos District and Happy Canyon of Santa Barbara. It boasts an impressive collection of climates and soils, and among the most diverse collection of winegrape plantings in the world. Because the AVA has a large east-west span with a series of north-south hills in between, it experiences a great deal of climatic variation. In general, it’s a bit warmer than the Santa Maria AVA at similar distances from the ocean. Average annual rainfall ranges from 10 to 17 inches.