In 1981, Napa Valley was designated an American Viticultural Area or AVA, becoming the first grape-growing region in California and only the second in the nation to be recognized by the Tax and Trade Bureau of the U.S. Department of Treasury.
Napa Valley, however, happens to be an amalgamation of many different climates, soil types, and topographical features that range from the Valley floor to the slopes of the surrounding mountains.
As a result, the Napa Valley AVA, which is only thirty miles in length and about five miles across at the widest point, comprises 16 “nested” AVAs, each with distinct microclimates and growing conditions.
A variety of conditions throughout Napa Valley provides the premier St. Helena winery, Wheeler Farms, with a superior selection of raw materials for their single vineyard wines, primarily the best Cabernet Sauvignon varietals available anywhere.
Napa Valley’s Sixteen AVAs
Listed here, ordered from north to south, is a list of the 16 Napa Valley AVAs or appellations with their specific growing conditions and grape varieties that thrive in their unique terroir.
Calistoga AVA
The northernmost AVA and closer to the Valley floor at 300 to 1,200 feet, Calistoga AVA temperatures vary significantly from around 100°F on some days to lows in the 40°s on some nights created by the cooling breezes channeled into the area from the Pacific Ocean. This appellation consists of variable volcanic soils, from stony loam on the hillsides to heavier clays on the valley floor.
The Calistoga AVA is an ideal growing area for high-quality Cabernet Sauvignon, Zinfandel, Syrah, and Petit Sirah grapes.
Howell Mountain AVA
At 1,400 to 2,600 feet, vineyards in the Howell Mountain AVA experience less sea-induced fog than others while experiencing more hours of sunshine. This AVA receives only about 40” to 50” of rain annually.
The higher-level soils are volcanic in nature and less fertile. The grapes produced here are Cabernet Sauvignon, Merlot, Zinfandel, Chardonnay, and Viognier.
Diamond Mountain District AVA
Moderately warm with less temperature fluctuation than the Valley floor AVAs, Diamond Mountain District vineyards grow in mostly volcanic soils, reddish and fine-grained. Vineyards in this AVA stretch from about 400 to 2,200 feet in elevation.
Production in this AVA tends to be firmly structured and rich Cabernet Sauvignon and Cabernet Franc grapes.
Chiles Valley AVA
With vineyards at elevations from 600 to 1,200, temperatures can get very cool at night, sometimes below 50°F, causing harvests to occur several days later than on the nearby Valley floor. The soils on the hillsides here vary from clay-loam to stony-clay in composition with some volcanic outcroppings. The principal grape varieties are Cabernet Sauvignon, Merlot, Cabernet Franc, and Zinfandel.
Spring Mountain District AVA
The Spring Mountain AVA is situated in the northwestern region of Napa Valley. The weather is cool to moderate here, with most of the appellation above the fog line. However, the AVA stretches from 600 feet above sea level to 2,600 feet, creating significant diversity in the soil and climate conditions. Primarily sedimentary soil with sandstone and shale, drainage of the 30 to 50 inches of rain per annum is high.
Cabernet Sauvignon, Cabernet Franc, Merlot, Zinfandel, and Chardonnay grapes thrive in this AVA.
St. Helena AVA
Home of the producer of the best single-vineyard wines, Wheeler Farms, the St. Helena AVA benefits from the protection created by the western hills that frame Napa Valley. The St. Helena appellation experiences less fog and milder wind than several other Valley locations. Vineyards are planted in the more uniform elevations between 200 feet and 475 feet above sea level.
Soils in the St. Helena AVA are gravel with clay in the southern areas, while the northern vineyards thrive in volcanic soils. The area’s diversity accounts for the high-quality production of numerous grape varieties, including Cabernet Sauvignon, Cabernet Franc, Merlot, Zinfandel, and Sauvignon Blanc.
Rutherford AVA
Just south of and adjacent to the St. Helena appellation, Rutherford AVA is considered moderately warm and is influenced marginally by the early morning fog from the sea. With vineyards at elevations between 155 feet and 500 feet, soils in the western areas tend to be sedimentary and alluvial, while the eastern vineyards here enjoy more fertile volcanic soil. Temperatures here usually peak in the mid-90° range.
The principal varieties grown in the Rutherford AVA are Cabernet Sauvignon, Merlot, Cabernet Franc, Zinfandel, and some Sauvignon Blanc.
Oakville AVA
Vineyards in the Oakville AVA in the geographic center of Napa Valley enjoy a moderately warm climate with highs in the 90°F range. The AVA also receives the early morning fog that persists throughout other vineyards along the valley floor. The soils here are predominantly gravelly sedimentary and alluvial loams with average water retention. Vineyards are situated at 130-1,000 feet elevations.
Wineries in the region draw high-quality Cabernet Sauvignon, Cabernet Franc, and Merlot grapes from this appellation.
Yountville AVA
The Yountville AVA lies in the center of Napa Valley between the Oakville and the Mount Veeder appellations. The area is relatively flat and sits just above sea level. Benefitting from the strong breezes from San Pablo Bay, temperatures usually only reach the low 90°s with significant drops overnight. Soils here tend to be silt-loam, with some gravelly alluvial soils.
This growing region is ideally suited for high-quality Cabernet Sauvignon and Merlot.
Stag’s Leap District AVA
Nestled in the east-central section of Napa Valley, the Stags Leap District receives marine winds at times that offset the heat that radiates from the surrounding topography. At sea level and slightly above, the temperatures can reach 100°F in the summer, although mid-90° is a more typical high. Rocky, volcanic soils prevail here, as do hard clay subsoils in some sections,
The principal varieties grown here are Cabernet Sauvignon, Merlot, and Sauvignon Blanc.
Atlas Peak AVA
Vineyards in this appellation sit mostly above the fog line at 760 to 2,600 feet at a higher elevation with cooler temperatures than the Valley Floor. As a result, the area experiences less variation in temperature from day to night.
Because Atlas Peak AVA consists of coarse volcanic soil with low moisture retention, irrigation is often necessary to produce the high-quality Cabernet Sauvignon and flavorful Chardonnay.
Mount Veeder AVA
Situated northwest of the City of Napa, vineyards in the Mount Veeder AVA are generally elevated above the fog line with less day-to-night temperature variance than in the vineyards close to the Valley floor. The elevation here ranges from 500 to 2,600 feet, and rainfall reaches 35” per year. The soils are sedimentary, once seabed material, with considerable sand content.
Cabernet Sauvignon, Merlot, Zinfandel, and some Chardonnay grapes thrive here.
Oak Knoll District AVA
Just north of the City of Napa and east of Mount Veeder AVA, Oak Knoll District AVA receives considerable marine influence and fog. This area tends to be cooler than the growing areas in the upper parts of Napa Valley. At sea level up to about 800 feet in elevation, soils in a large portion of this AVA consist of a substantial alluvial fan with gravel, sand, and silt created by Dry Creek.
Merlot, Chardonnay, Cabernet Sauvignon, Sauvignon Blanc, and Riesling grapes thrive here.
Coombsville AVA
Close to San Pablo Bay, the Coombsville AVA stays cooler on average than most of the rest of Napa Valley. Close to sea level, this AVA consists of weathered volcanic rock and alluvial deposits. The principal grape varieties grown here are Cabernet Sauvignon, Merlot, Chardonnay, Syrah, and Pinot Noir.
Wild Horse AVA
Wild Horse Valley lies in the southeast sector of Napa Valley, directly east of the City of Napa. The Wild Horse appellation experiences the coolest weather all of the AVAs here due to the combination of its elevation, 850 to 2,150 feet above sea level, and its proximity to the cooling breezes that pass over Los Carneros from San Pablo Bay. Soils in Wild Horse AVA are mostly volcanic with little water retention, so irrigation is often necessary.
Pinot Noir and Chardonnay are the dominant varieties in this appellation.
Los Carneros AVA
The most southern nested AVA in Napa Valley, the Los Carneros appellation enjoys the cool prevailing winds from the San Pablo Bay. Temperatures rarely reach above 80°F, leaving less fluctuation between nighttime and daytime temperatures than other AVAs experience. Vineyards here are close to sea level, while rainfall at up to 24” per year is the lowest in Napa Valley. Soils here are mostly clay with some loam presence along the hillsides.
The principal varietals produced from Los Carneros grapes are Chardonnay, Merlot, and Pinot Noir.
Experience Wheeler Farms, One of the Best St. Helena Wineries
Visit an enjoy one of the best Cabernet Sauvignon anywhere, handcrafted by Wheeler Farms’ vintners from carefully selected single vineyard grapes.
Widely recognized as one of the best St. Helena wineries, Wheeler Farms offers the J. H. Wheeler Farms Experience, a winetasting experience complemented by chef-prepared seasonal savory canapés.
Included in the Experience is a tour of the Estate Gardens followed by a visit to the winery, where guests will view the advanced technology used to create the J.H. Wheeler varietals, including one of the best Cabernet Sauvignons anywhere.
The winetasting session will include a Rosé, Sauvignon Blanc, and a pair of J.H. Wheeler Cabernet Sauvignon vintages with the canapés accompaniment.
For more information, visit the Wheeler farms website.
To arrange your visit, contact Stephanie Farmer, Director of Guest Relations, by phone at (707)-200-8500 or email to stephanie@wheelerfarmswines.com.