The idea of terroir is often used to describe the unique combination of environmental factors that contribute to the distinct characteristics of a region’s wines. While Napa and Sonoma are often referred to interchangeably, these two wine regions are actually quite different, with distinct geology, climate, and terroir that result in a wide range of wines.

• The influence of the Pacific Ocean
• The temperature swings
• The diversity of climate and geology

Sonoma and Napa Valley are located next to each other, but their proximity to the Pacific Ocean and the impact it has on the region’s climate and terroir, are a key differentiator. Sonoma’s coastal location means that the Pacific Ocean plays a significant role in shaping the profiles of the wines produced in the region. In contrast, Napa Valley’s inland location results in more dramatic temperature swings, with hotter days and cooler nights. The climate and terroir of the two regions are incredibly complex, with a range of microclimates that can be found across Napa and Sonoma. Elizabeth Tangney, winemaker of Cornell Vineyards in Sonoma County, notes that the diversity in climate and geology can be found across both regions, but that Napa’s diversity is more compact and confined between two mountain ranges. Sonoma, on the other hand, has a larger footprint that spans coastal, mountain, inland, and sea-level regions, and boasts a greater variety of grape types and farming styles.

The Grapes and the Wines

Because of their differences, the grape varieties cultivated in each region are famously different. Napa Valley is renowned for its Cabernet Sauvignon, in addition to other classic Bordeaux grape varieties like Merlot and Cabernet Franc. Producers like Harlan Estate, Screaming Eagle, and Schrader are highly sought-after for their Cabernet Sauvignon, and the wines are known for their richness and generosity of ripe fruit. In contrast, Sonoma is known for its Pinot Noir and Chardonnay, with each appellation leaving its distinct style on the wines. The Russian River Valley is particularly famous for its Pinot Noirs, with wines that are effusive, fruity, and spicy. The West Sonoma Coast AVA, on the other hand, produces more tautly acidic and ocean-influenced Chardonnays.

Region	Key Wine Style	Notable Producers
Napa Valley	Cabernet Sauvignon	Harlan Estate, Screaming Eagle, Schrader
Russian River Valley	Pinot Noir	Chateau Ste. Michelle, Jordan, Korbel
West Sonoma Coast AVA	Chardonnay	La Crema, Sebastiani Vineyards, Kendall-Jackson

A Microclimate is Key

The microclimates in Napa and Sonoma are critically important, and the nuances of individual pockets are unique to each region. Avedisian-Cohen uses an analogy to compare the two regions, likening Napa to Manhattan and Sonoma to Brooklyn.