Local Terroir
Geological Influences
Napa Valley is one of the world’s preeminent wine regions thanks to its unusual combination of climate, soils, and topography. Napa Valley lies east of Sonoma County. The Valley is located at the northern end of San Pablo Bay, framed on the west by the Mayacamas Mountains and by the Vaca Mountains to the east. It is 30 miles (48 km) long by 5 miles (8 km) at its widest point.
Geologically, Napa Valley is fairly young. The entire California region sits on a “transform fault zone,” a place where two tectonic plates slide past each other. Here the movement of the Pacific plate and the North American plate creates the San Andreas fault zone that traverses 600 miles (966 km) through California. Over 30 million years ago, creation of this fault zone enabled periodic volcanic activity. Thus, volcanic rock over eight million years old can be found in parts of Napa Valley.
Another tectonic plate helped form Napa Valley over 40 million years ago. At that time, the Farallon plate in the Pacific was subducting, or going under, the North American plate. As one plate moved under the other, material was scraped off and deposited on the surface. Today the western part of Northern California has a myriad of mineral-rich volcanic soils, as well as sedimentary rock from both the ancient sea floor and California Central Valley.
Mountains and River
Over the last 150-million-plus years, movement of tectonic plates and volcanic activity have created two mountain ranges that border the valley on each side: the Mayacamas Mountains to the west and the Vaca Mountains to the east, both part of the Coastal Ranges which span over 400 miles (644 km) from Humboldt County in the north to Santa Barbara County in the south.
The Mayacamas Mountains act as a rain shadow, lessening the impact of Pacific storm systems in winter, as well as overall fog and marine influence from the ocean. In the east, the Vaca range protects the Valley’s vineyards from the extreme heat of the Central Valley in the summer.
Individual peaks give their names to some of Napa Valley’s best-known sub-regional AVAs, home to distinctive “mountain wines.” Famous peaks in the Mayacamas range include Diamond Mountain at 2,375 feet (724 meters), Mount Veeder at 2,680 feet (817 meters), and Mount St. Helena, the highest, at 4,341 feet (1,323 meters). In the Vaca range, Mount Vaca is the highest point at 2,818 feet (859 meters), with Atlas Peak at 2,663 feet (812 meters), and Howell Mountain at 1,683 feet (513 meters).
The Napa River runs approximately 55 miles (89 km) through the heart of the Napa Valley. The river rises in northwestern Napa County, just south of the summit of Mount St. Helena. It enters the valley north of Calistoga, then flows southeast past the towns of St. Helena, Rutherford, Oakville, and through the city of Napa. South of Napa it forms a tidal estuary, entering the Mare Island Strait before emptying into San Pablo Bay through the Napa-Sonoma Marsh.
The Napa River watershed is approximately 425 square miles (684 square km) in size and supports an assortment of fish and wildlife; however, the river is also prone to periodic flooding – affecting vineyards – during rainy winter months. There are 23 floods on record since 1865. The worst occurred in 1986 when over 5,000 people had to be evacuated with 250 homes destroyed and three fatalities. After that flood the Napa River Flood Project was undertaken. Construction began in 2000 and was completed by 2015.
Soil Diversity
Napa Valley’s diversity of soil types is a major reason the area is one of the world’s preeminent wine regions. In particular, the valley’s volcanic soils are especially suited to growing Cabernet Sauvignon and other Bordeaux varieties. But the formation of modern day Napa’s soils happened over the last several million years. During that time a combination of weather, microbial activity, and earthquakes has helped create over 100 distinct soil types, 33 different soil series, and half the world’s recognized soil orders.
Volcanic soils in the Napa Valley region are the result of massive volcanic eruptions that covered Northern California over 30 million years ago. Almost all of the Vaca Range and a substantial part of the Mayacamas (particularly part of Spring Mountain and north) are primarily volcanic. Mountain appellations like the Atlas Peak AVA contain soils comprised of igneous and lava gravel rock. Here, red grapes such as Cabernet Sauvignon and Merlot do well and the wines are deep, concentrated, and powerful.
Throughout the valley, alluvial fans between the hillsides and valley floor, called “Napa Benches” are ideally suited to growing vines. The Rutherford Bench in the Rutherford AVA is the most well-known of the Napa Benches and has long been famous for some of the valley’s best Cabernet Sauvignons. On hillsides, loose weathered rock, gravel, and soil have washed downslope over time forming colluvial deposits. Coombsville AVA, in the southeastern part of the valley, has hillside colluvial soils. Outstanding Merlot, Chardonnay, Syrah and Pinot Noir are made from vineyards planted here.
On the valley floor, movement of rocks, gravel, and soil from the movement of the Napa River over time has created alluvial soils excellent for growing Cabernet family grapes. In other places on the valley floor, deeper sandy loam soils are better for white grapes such as Sauvignon Blanc.
In the Los Carneros AVA at the southern end of the Valley near the San Pablo Bay, the soils are marine sedimentary clay with underlying sandstone. In particular, a mixed marine clay soil called the “Haire Series” has been successful in cultivating high quality Chardonnay and Pinot Noir.
Climate
Napa Valley has a dry Mediterranean climate with warm summers, cooler winters, and a preponderance of rainfall between November and March. The Pacific with its cold ocean currents is the dominant influence on Napa Valley’s climate. The cold air penetrates into the region through the San Pablo Bay and Petaluma wind gap in the south, and through a gap in the Mayacamas Range in the far northern parts of the valley. Fog from San Pablo Bay also mitigates hot temperatures during the growing season.
Fog plays an important role in the valley’s climate and micro-climates. On average, Sonoma County has much more fog due to several west-east-situated valleys. The Mayacamas Mountains on the west side of the Valley act as a barrier to fog from the Pacific coast. However, considerable fog makes its way up-valley from San Pablo Bay and a lesser amount from the Chalk Hill Gap at the far northern end of the Valley.
Fog directly impacts the diurnal shift (hyperlink), the difference between the warmest daytime temperature and coolest night time temperature. During the growing season, morning fog from San Pablo Bay makes its way up the valley as far as St. Helena. As morning temperatures rise, the fog burns off and is usually gone by early afternoon.
Typical daytime temperatures during the growing season vary depending on proximity to San Pablo Bay. In the southern part of the Valley, where there is more fog, wind, and marine influence, the average daytime temperature is 80°F (27°C). Up-valley, north of the town of St. Helena, it’s significantly warmer, with daytime temperatures averaging 95°F (35°C) in summer. An exception to this rule is the northern reaches of Calistoga, where cooling breezes come through the Chalk Hill gap. The hillsides in Napa Valley are generally cooler than the valley floor due to elevation, but generally receive more hours of sun as many are above the fog line (1,600 ft/488 m). Eastern facing vineyards on the Mayacamas are generally cooler than the western falling vineyards on the Vaca Range.
As the region has a dry Mediterranean climate, over 70% of annual rainfall takes place between December and March. On average, Napa Valley receives 20 inches (51 cm) of rain. However, yearly rainfall totals vary according to location, with 22-23 inches (56-58 cm) in the city of Napa, 36-37 inches (91-94 cm) in Calistoga, and 59-60 inches (150-152 cm) at Mt. St. Helena in the far north end of the valley. The two mountain ranges receive the highest rainfall totals with less on the valley floor.
The combination of a long growing season, Mediterranean climate, and considerable diurnal shift between warm summer days and cool foggy nights are another reason why Napa Valley is one of the world’s great wine regions. Further, the micro-climate variations within the valley’s sub-regions, from Los Carneros in the south to St. Helena in the north help create a diversity of grape varieties grown and wines made.
Sub-AVA's
Location/Geography
Lying between the Mayacamas Range on the west and the Vaca Range on the east, the Calistoga AVA (American Viticultural Area) lies at the northernmost end of the Napa Valley. From the foot of Mount St. Helena, the appellation stretches approximately seven square miles before brushing against the St Helena, Diamond Mountain and Howell Mountain AVAs.
Name Background
Calistoga’s colorful personality is a reflection of its history. The geothermal waters that bubble to the earth’s surface here are rich in magnesium and calcium, which first attracted the Native Americans who gathered here for detoxification and purification. It wasn’t just the water that attracted trailblazers: the volcanic soils attracted those who preferred wine to water, starting as early as 1862. In the early 1870s, Sam Brannan arrived. His vision was to turn the waters into a world-class spa destination to be known as the “Saratoga of California.” But after imbibing a bit too much brandy at a dinner party, he misspoke, proclaiming the place the “Calistoga of Sarafornia” – and the name stuck: in 1886, the town was incorporated as Calistoga.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 300 to 1200 feet (92 to 370 m)
Rainfall: up to 60 inches (96.5 to 150 cm) annually
Geology/Soil Composition
Almost completely of volcanic origin, soils range from rocky, stony loam on the hillsides, to gravelly or cobbly loams on the alluvial fans, and heavier clay-silt soils in the valley center areas.
Climate
Warm to hot, depending upon time of year. Calistoga AVA has the most extreme diurnal swing in Napa Valley of all AVAs, meaning the day time and night time change in temps is very large. Daytime summer temperatures may peak above 100° (38°C) and fall to low 40s°(6°C) at night due to cool afternoon and evening breezes drawn in from the Chalk Hill Gap from the Pacific.
Main Grape Varieties
Cabernet Sauvignon, Zinfandel, Syrah, Petite Sirah
Location/Geography
Located in the southeastern corner of the Napa Valley, tucked up against the foothills of the Vacas Range, just outside of this historic city of Napa.
Name Background
The Coombsville AVA is named for an area of the city of Napa called Coombsville. It's namesake was Nathan Coombs, one of the founders of the city of Napa and a large landholder there.
Topography/Elevation/Water Sources/Geographic Features
Elevation:100-1000 feet (30-305 m)
Rainfall: 25 inches (65 cm) annually
Geology/Soil Composition
Primarily weathered volcanic rock and alluvial deposits from the Vaca Range that surrounds the region
Climate
Weather is moderated by its proximity to the San Pablo Bay. Daily average high temperatures can be as much as 10 degrees cooler during the hot months than most other AVAs, and heat spikes tend to be less severe.
Main Grape Varieties
Dominated by Cabernet Sauvignon on the hillsides with Merlot, Chardonnay, Syrah and Pinot Noir in the lower, cooler sites
Location/Geography
Carneros is the only appellation located at the crossroads of two major wine regions, the Napa and Sonoma Valleys. Surrounded by Napa Road on the outskirts of the town of Sonoma to the North, the low southern hills of the Mayacamas Range and the Napa River to the East, the wetlands and hayfields skirting San Pablo Bay to the South, and to the West, the border is shared with Sonoma Valley, along the spine of hills dividing Cotati Valley (and the Petaluma Gap area) from the Sonoma Creek watershed.
Name Background
In the 1830s, under Mexican rule, the generals began awarding large land grants to prominent military personnel and citizens, making way for the shift from sacramental wine to commercial vineyards. The name “Los Carneros” itself is connected to one of the original land grants —Rincon de los Carneros (“corner of the rams”), but that land lies in what today is Monterey County.
Topography/Elevation/Water Sources/Geographic Features
San Pablo Bay itself is the overarching influence in Los Carneros, dictating temperatures, diurnal swings (or lack of), and the potential length of the growing season across the board. The Pacific Ocean is close enough on the west to influence the vineyards to a lesser extent on the Sonoma side of the AVA.
Elevation: Sea level to 700 feet (0 to 213 m)
Rainfall: Lowest in Napa Valley: up to 24 inches (10 cm) annually.
Soil Composition
Clay dominated, very shallow in general, with more loam and hillside alluvials in the northern section. Yields typically are restrained by the hard claypan subsoil, which prevents deep-rooting.
Climate
Cool, with prevailing marine winds from the San Pablo Bay and through the Petaluma Gap to the west. High temperatures during summer rarely exceed 80°F (27°C) with less diurnal range variation.
Main Grape Varieties
Pinot Noir, Chardonnay, Merlot and Syrah
Location/Geography
The District lies at the southern reaches of Napa Valley. Its location near San Pablo Bay means it is one of Napa's cooler AVAs.
Name Background
Captain Joseph W. Osborne, with the Gold Rush booming, settled in California in 1850. The following year he purchased a large tract of land three miles south of Yountville and named it Oak Knoll. In 1852 he brought vine cuttings introducing some of the first European grape varieties to California.
Topography/Elevation/Water Sources/Geographic Features
Elevation: sea level to 800 feet (244 m)
Rainfall: 36 inches (90 cm) annually.
Geology/Soil Composition
The valley's largest alluvial fan formed by Dry Creek creates the defining feature of the district. The northwest area is composed of volcanically derived soils, with stony or gravelly consistency. South and east areas are transitional from gravel to silty clay loam.
Climate
Moderate to cool: marine air and fog can remain until late-morning. Late afternoon breezes frequently occur, maintaining slightly cooler temperatures than upper valley. Mid-summer temperatures may reach 92° F (33°C) and drop to around 50°F (10°C) at night.
Main Grape Varieties
Merlot, Chardonnay, Cabernet Sauvignon, Sauvignon Blanc and Riesling
Location/Geography
Located in the heart of Napa Valley, this two mile (3 km) wide AVA extends to 1,000 feet (305 m) in elevation up the base of the Vaca Mountains to the east and 500 feet (152 m) in elevation in the Mayacamas Mountains to the west.
Name Background
Once a steam train stop in the late 1800s, Oakville owes its name to the dense groves of native oak which once blanketed the area.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 130 - 1000 feet (40 to 305 m).
Rainfall: 35 inches (87.5 cm) annually.
Geology/Soil Composition
Primarily sedimentary gravelly alluvial loams on the western side, with more volcanic but heavier soils on the eastern side. Low to moderate fertility and fairly deep, with average water retention.
Climate
Moderately warm, with temperatures commonly in the mid-90°F (34-35.5°C) range in high summer, but also still strongly affected by night and early morning fog, which helps keep acidity levels good. East side of the AVA receives warmer afternoon sun.
Main Grape Varieties
Cabernet Sauvignon, Cabernet Franc, Merlot, Sauvignon Blanc
Location/Geography
Located south of St Helena and immediately north of Oakville, at the heart of the Napa Valley winegrowing area.
Name Background
named after Thomas Lewis Rutherford, who married Elizabeth Yount, granddaughter of Napa's pioneering vigneron George C. Yount.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 155 to 500 feet (47 to 152 m).
Rainfall: 38 inches (95 cm) annually.
Geology/Soil Composition
Western benchland is sedimentary, gravelly-sandy and alluvial, with good water retention and moderate fertility. The eastern side has more volcanic soils, moderately deep and more fertile.
Climate
Moderately warm, still marginally influenced by early morning fog. Western bench area is cooler, with less late afternoon sun, tempered by afternoon marine winds. (This AVA averages a bit warmer than Oakville and Stags Leap District). Usual summer peak temperatures are mid-90°F (34-35.5°C) with a large diurnal range.
Main Grape Varieties
Cabernet Sauvignon, Merlot, Cabernet Franc, Zinfandel, Sauvignon Blanc
Location/Geography
In the middle of Napa Valley, north of Rutherford and south of Calistoga. Boundaries defined by Zinfandel Lane to the south, Bale Lane to the north, the intersection of Howell Mountain and Conn Valley Road to the east, and the 400 foot (122 m) elevation line of the Mayacamas Mountain range to the west
Name Background
AVA is centered around the town of St. Helena
Topography/Elevation/Water Sources/Geographic Features
Elevation: 200 to 475 feet (46 to 145 m).
Rainfall: 38 to 40 inches (95 to 101 cm) annually.
Geology/Soil Composition
South and west borders are more sedimentary, gravel-clay soils, with lower fertility and moderate water retention. Further north and to the east soils are prevalently volcanic in origin and are deeper and more fertile.
Climate
Warm, due to greater protection from western hills, with less fog or wind incursions. This narrowest part of the Napa Valley floor floor provides more heat reflection off the hillsides. Mid-summer temperature peak is often in mid-to-high 90°s (35° to 37°C).
Main Grape Varieties
Cabernet Sauvignon, Cabernet Franc, Merlot, Syrah, Zinfandel, Sauvignon Blanc
Location/Geography
Often referred to as a "valley within a valley," the district is bounded on the east by the towering Stags Leap Palisades, to the west by the gently rolling hills and the Napa River, to the north by the Yountville Cross Road, and to the south by low-lying flatlands.
Name Background
In 1893, San Francisco entrepreneur Horace Chase built the first winery to bear the Stags' Leap name. Theories abound as to the origin of the name Stags Leap but the most well loved and oft-repeated is the legend of a stag who successfully eluded hungry hunters by leaping to freedom across the District's landmark peaks. A jagged outcropping of sheer rock and the legend of this nimble buck inspired the Stags Leap AVA name over a century ago.
Topography/Elevation/Water Sources/Geographic Features
Elevation: Sea level to 400 feet (20 to 123 m).
Rainfall: 30 inches (75 cm) annually.
Geology/Soil Composition
Volcanic gravel-loams on the floor of the valley, with rocky hillsides, and low to moderate fertility due to hard clay subsoils.
Climate
Moderately warm with afternoon marine winds acting as an "air-conditioner" to cool the warmer air radiating off the bare rocks of Stags Leap itself and the surrounding hillsides. Mid-summer temperatures can reach 100°F (37.7°C), but more regularly are in mid-90° range (34° to 36°C).
Main Grape Varieties
Cabernet Sauvignon, Merlot, Sauvignon Blanc
Location/Geography
Located in the heart of the Napa Valley, halfway between the northern shores of San Pablo Bay and the southern slopes of Mount St Helena. The AVA surrounds the town of Yountville that lies partway between the city of Napa and St Helena.
Name Background
Yountville is named after George C. Yount, the settler who planted Napa's very first vineyard at Rancho Caymus in the 1830s.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 20 to 200 feet(6 to 61 m).
Rainfall: 32 inches (80 cm) annually.
Geology/Soil Composition
Principally gravelly silt loams, sedimentary in origin, and gravelly alluvial soils with rock, moderately fertile.
Climate
Moderate, with cool marine influence and fog contributing to cool summer mornings and the strong breezes of San Pablo Bay keeping afternoons more comfortable than further up valley. Mid-summer peak temperatures may reach low 90°F (33°C), with noticeable diurnal fluctuation to the mid-50°F range (13°C).
Main Grape Varieties
Cabernet Sauvignon and Merlot
Hillside AVA’s
Location/Geography
Located on the western slopes of the Vaca Range, which separates the Napa and Sacramento valleys.
Name Background
Named for Atlas Peak, the most prominent peak in the region at 2,663 ft (812 m).
Topography/Elevation/Water Sources/Geographic Features
Elevation: 760 to 2600 feet(232 to 792 m).
Rainfall: 38 inches (96 cm) annually.
Geology/Soil Composition
Volcanic in origin, with basaltic red color, shallow with limited water retention, so irrigation is often essential.
Climate
Cool, mountain influenced with temperatures about 10–15°F (6-8°C) cooler than the valley floor in summer; above the fog line, there is low day-to-night temperature range, with summer temperatures rarely rising above 90°F (32°C)
Main Grape Varieties
Known for Bordeaux varieties, with Cabernet Sauvignon most prominent. You can also find Cabernet Franc, Chardonnay, Malbec, Marsanne, Merlot, Petit Verdot, Sangiovese, Sauvignon Blanc, Syrah and Zinfandel
Location/Geography
Chiles Valley is a small AVA in the eastern hills of California's Napa Valley wine region. Chiles Valley resembles a long, thin scar slicing through the hillside between St Helena and Lake Berryessa.
Name Background
In 1841 Joseph Ballinger Chiles, a man from Missouri who fought in the Seminole Wars and was granted Mexican Citizenship, was given a two league piece of land known as Rancho Catacula by Governor Manuel Micheltorena. It covered the land east of St. Helena in the Chiles Valley along Chiles Creek. A claim was filed in 1852 but it wasn’t until 1865 that a grant was issued to Joseph Ballinger Chiles. The Chiles House, built in 1856 is one of the oldest homes in Napa Valley.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 600 to 1200 feet (182 to 366 m).
Rainfall: 35 inches (88 cm) annually.
Geology/Soil Composition
On the valley floor, primarily alluvial soils with silty-clay composition of marine origin, with good fertility. Hillsides show more clay-loam and stony-clay composition, mostly marine in origin, with some volcanic outcropping, and less fertility.
Climate
Fairly warmer summer days (mid-80°F plus/28.8 to 31°C), but due to higher elevation and summer fog at night, quite chilly at night (below 50°F/10°C). With colder winters and spring, as well as strong winds, harvest comes later than on valley floor at Oakville.
Main Grape Varieties
Cabernet Sauvignon, Merlot, Cabernet Franc & Zinfandel
Location/Geography
Located in the Mayacamas Mountains in the northwest portion of the Napa Valley AVA above Calistoga.
Name Background
Named after Diamond Mountain
Topography/Elevation/Water Sources/Geographic Features
Elevation: 400 to 2200 feet (122 to 671 m)
Rainfall: 40 to 55 inches (135 cm) annually.
Geology/Soil Composition
Residual uplifted soils of volcanic origin, often reddish and very fine-grained, even gritty in texture, composed of both weathered sedimentary and volcanic origin.
Climate
Moderately warm temperatures with lower maximum temperatures and higher minimum temperatures than the valley floor, due to topography and altitude. 50 to 90°F in growing season (10 to 32°C).
Main Grape Varieties
Cabernet Sauvignon and Cabernet Franc
Location/Geography
Due east of St. Helena. Howell Mountain is located in the Vaca Mountain Range, and the AVA itself is defined as anything above the 1,400 ft (427 m) elevation point on the mountain, so the Howell Mountain appellation is literally a mountain top on the eastern side of Napa Valley.
Name Background
Howell Mountain and the entire mountain range took its name from the Isaac Howell family who moved to the mountain range in 1846.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 1400 to 2600 feet (427 to 792 m).
Rainfall: 40 to 50 inches (125 cm) annually.
Geology/Soil Composition
Predominantly volcanic, shallow and infertile. Drainage is high, fertility low.
Climate
Located above the fog line on the eastern side of the valley, the AVA is warmer and drier than other AVAs with more hours of sunshine and little-to-no marine influence.
Main Grape Varieties
Cabernet Sauvignon, Merlot, Zinfandel, Chardonnay, Viognier
Location/Geography
Napa Valley, west of Napa and Yountville, within the Mayacamas Range. The only one of the five Napa Valley mountain appellations that adjoins the cool Carneros District.
Name Background
Mount Veeder was named for the Dutch Presbyterian pastor, Peter Veeder, who lived in Napa during the Civil War Era.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 500 to 2600 feet (152 to 792 m).
Rainfall: 35 inches (87.5 cm) annually.
Geology/Soil Composition
Sedimentary based, former seabed, shallow and generally well drained, as well as more acidic, with low fertility. Most have a sandy or sandy-loam texture.
Climate
Cool to moderate, with most vineyards above the fog-line, meaning warmer nights and cooler days and less diurnal range than the valley floor. Typical mid-summer high temperatures about 85°F (29°C).
Main Grape Varieties
Cabernet Sauvignon, Merlot, Zinfandel, Chardonnay
Location/Geography
Located at a low point in the Mayacamas Mountains on the western side of the Napa Valley. The AVA is one of the more northerly in Napa, covering 8,600 acres (3,480 hectares) of rolling vineyard, scrubland and forest in the hills just south of Diamond Mountain District and Calistoga.
Name Background
Named for natural springs that surface throughout the region, Spring Mountain is not a single peak, rather a group of mountains.
Topography/Elevation/Water Sources/Geographic Features
Elevation: 600 to 2600 feet (183 to 792 m).
Rainfall: 40 to 50 inches (125 cm) annually.
Geology/Soil Composition
Primarily sedimentary; weathered sandstone/shale, loamy and friable in texture. Drainage is high, fertility low.
Climate
Cool to moderate depending on elevation and aspect. Most vineyards sit above the fog line, providing wrmer nights and cooler days than the valley floor. typical mid-summer high temperatures reach 85° (29°C).
Main Grape Varieties
Cabernet Sauvignon, Cabernet Franc, Merlot, Zinfandel, Chardonnay
Location/Geography
Located in the Vaca Mountains above the city of Napa. The AVA is one of the smallest in the United States, covering just 1350 hectares (3300 acres) of land on the hills above Coombsville.
Name Background
The very first grapes were planted in the 1880’s by Joseph Volpe and Contsantino Malandrino. Back then the area was home to many wild horses, hence the name!
Topography/Elevation/Water Sources/Geographic Features
Elevation: 850 to 2130 feet (259 to 650 m).
Rainfall: 35 inches (94 cm) annually.
Geology/Soil Composition
Volcanic in origin, with basaltic red color, shallow with limited water retention, so irrigation is often essential.
Climate
Due to elevation and proximity to San Pablo Bay, it is the coolest of all the Napa Valley AVAs. The air mass that passes over Carneros cools another 10 degrees by the time it rises to the AVA.
Main Grape Varieties
Pinot Noir and Chardonnay
