Although Napa Valley is California’s most famous wine region, it is the source of barely five per cent of the state’s total wine production. But in Napa, quality makes up for quantity. The diverse climatic conditions and 150 recorded soil types in the valley explain the diversity of grape varietals. The different winemaking styles and the characteristics of each vintage also result in a broad range of wines. The Cabernet Sauvignon grown here can be exceptional and the valley’s best wines are undoubtedly among the finest in the world. Noble grape varieties such as Chardonnay, Zinfandel, Pinot Noir, Cabernet Franc, and Merlot also do well in the Napa terroir. This narrow valley stretches over 48 km (5 km at its widest point) and has approximately 14,000 hectares of vineyards. The valley is much cooler in the south (6.3°C on average) because of its proximity to San Francisco Bay.