The experts agree – in 1981, Napa Valley was named California’s first AVA.
During the early years of winemaking in the Napa Valley, vineyards were often planted in patchwork patterns with many varieties growing side by side, as the practice of matching the most appropriate grape varieties to the particular soil and climatic conditions of a vineyard site was little understood at best. As Napa Valley became better known, vintners decided to market our wines collectively to distinguish them from and compare them to the wines of the great wine regions of the world.
Today, we have an intimate understanding of the connection between terroir and vine and have realized just how the diversity of Napa Valley’s soil, climate and terrain allow us to grow distinctive wines from specific areas within the valley.
This great diversity has led our vintners and growers to petition the government to create defined grape growing areas within Napa Valley, giving them names that reflect their regional designations. These areas are called American Viticultural Areas, or AVAs.
Napa Valley AVA
The Napa Valley is itself an AVA, and it has been since it received its own designation in 1981. It is California's first recognized AVA and the second in the United States. Within the Napa Valley AVA exist 16 nested AVAs, including: Atlas Peak, Calistoga, Chiles Valley, Coombsville, Diamond Mountain District, Howell
Mountain, Los Carneros, Mt. Veeder, Oak Knoll District of Napa Valley, Oakville, Rutherford, St. Helena, Spring Mountain District, Stags Leap District, Yountville and Wild Horse Valley.
Napa Valley Nested AVAs
- Climate: Cool, mountain influenced with temperatures about 10–15° 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°.
- Elevation: 760 to 2600 feet(232 to 792 m)
- Rainfall: Up to 38 inches (96 cm) annually
- Soils: Volcanic in origin, with basaltic red color, shallow with limited water retention, so irrigation is often essential.
- Principal varieties: Cabernet Sauvignon, Chardonnay
- Atlas Peak AVA
- Climate: Warm to hot, depending upon time of year. 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.
- Elevation: 300 to 1200 feet (92 to 370 m)
- Rainfall: Up to 60 inches (97 to 150 cm) annually
- Soils: 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
- Principal varieties: Cabernet Sauvignon, Zinfandel, Syrah, Petite Sirah
- Calistoga AVA
- 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.
- Elevation: 600 to 1200 feet (183 to 366 m)
- Rainfall: Up to 35 inches (89 cm) annually
- Soils: 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.
- Principal varieties & characteristics: Cabernet Sauvignon, Merlot, Cabernet Franc, Zinfandel
- Chiles Valley AVA
- 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.
- Elevation:100-1000 feet (30-305 m)
- Rainfall: Up to 25 inches (64 cm) annually
- Soils: Primarily weathered volcanic rock and alluvial deposits from the Vaca Range that surrounds the region
- Principal varieties: Cabernet Sauvignon, Chardonnay, Merlot, Syrah, Pinot Noir
- Coombsville AVA
- Climate: Moderately warm temperatures with lower maximum (90°F or 32°C) and higher minimum (50°F or 10°C) than the valley floor, due to topography and altitude. 50 to 90°F in growing season (10 to 32°C).
- Elevation: 400 to 2200 feet (122 to 671 m)
- Rainfall: Up to 55 inches (140 cm) annually
- Soils: Residual uplifted soils of volcanic origin, often reddish and very fine-grained, even gritty in texture, composed of both weathered sedimentary and volcanic origin.
- Principal varieties: Cabernet Sauvignon, Cabernet Franc
- Diamond Mountain District AVA
- 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.
- Elevation: 1400 to 2600 feet (427 to 792 m)
- Rainfall: Up to 50 inches (127 cm) annually
- Soils: Predominantly volcanic, shallow and infertile. Drainage is high, fertility low.
- Principal varieties: Cabernet Sauvignon, Merlot, Zinfandel, Chardonnay, Viognier
- Howell Mountain AVA
- 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.
- Elevation: Sea level to 700 feet (Sea level to 213 m)
- Rainfall: Lowest in Napa Valley: up to 24 inches (61 cm) annually
- Soils: 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.
- Principal varieties: Chardonnay, Merlot, Pinot Noir
- Los Carneros AVA
- 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).
- Elevation: 500 to 2600 feet (152 to 792 m)
- Rainfall: Up to 35 inches (89 cm) annually
- Soils: 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.
- Principal varieties: Cabernet Sauvignon, Chardonnay, Merlot, Zinfandel
- Mount Veeder AVA
- 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.
- Elevation: sea level to 800 feet (244 m)
- Rainfall: Up to 36 inches (91 cm) annually
- Soils: 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.
- Principal varieties: Cabernet Sauvignon, Chardonnay, Merlot, Sauvignon Blanc, Riesling
- Oak Knoll District of Napa Valley AVA
- 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.
- Elevation: 130 - 1000 feet (40 to 305 m)
- Rainfall: Up to 35 inches (89 cm) annually
- Soils: 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.
- Principal varieties: Cabernet Sauvignon, Sauvignon Blanc, Merlot, Cabernet Franc
- Oakville AVA
- 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.
- Elevation: 155 to 500 feet (47 to 152 m)
- Rainfall: Up to 38 inches (96 cm) annually
- Soils: 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.
- Principal varieties: Cabernet Sauvignon, Sauvignon Blanc, Merlot, Cabernet Franc
- Rutherford AVA
- 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).
- Elevation: 600 to 2600 feet (183 to 792 m)
- Rainfall: Up to 50 inches (127 cm) annually
- Soils: Primarily sedimentary; weathered sandstone/shale, loamy and friable in texture. Drainage is high, fertility low.
- Principal varieties: Cabernet Sauvignon, Merlot, Cabernet Franc, Chardonnay, Zinfandel
- Spring Mountain District AVA
- 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 tmid-to-high 90°s (35° to 37°C).
- Elevation: 200 to 475 feet (61 to 145 m)
- Rainfall: Up to 40 inches (102 cm) annually
- Soils: 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.
- Principal varieties: Cabernet Sauvignon, Cabernet Franc, Merlot, Syrah, Zinfandel, Sauvignon Blanc, Viogner
- St. Helena AVA
- 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 (38°C), but more regularly are in mid-90° range (35°C).
- Elevation: Sea level to 400 feet (Sea level to 122 m)
- Rainfall: Up to 30 inches (76 cm) annually
- Soils: Volcanic gravel-loams on the floor of the valley, with rocky hillsides, and low to moderate fertility due to hard clay subsoils.
- Principal varieties: Cabernet Sauvignon, Merlot, Sauvignon Blanc
- Stags Leap District AVA
- Climate: Due to elevation and prximity 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..
- Elevation: 850 to 2130 feet (259 to 649 m)
- Rainfall: Up to 35 inches (90 cm) annually
- Soils: Volcanic in origin, with basaltic red color, shallow with limited water retention, so irrigation is often essential.
- Principal varieties: Pinot Noir, Chardonnay
- Wild Horse Valley AVA
- 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 low90°F (33°C), with noticeable diurnal fluctuation to the mid-50°F range (13°C).
- Elevation: 20 to 200 feet(6 to 61 m)
- Rainfall: Up to 32 inches (81 cm) annually
- Soils: Principally gravelly silt loams, sedimentary in origin, and gravelly alluvial soils with rock, moderately fertile.
- Principal varieties: Cabernet Sauvignon, Merlot
- Yountville AVA
