San Pablo Bay vs. Petaluma Gap!

Although it is common knowledge that both Sonoma Valley and Napa Valley receive their primary fog from the same southern direction—from San Pablo Bay through Los Carneros—the fog and wind pathways differ significantly for our vineyard on the eastern slopes of Sonoma Mountain.

In Sonoma, fog also creeps in from the Pacific Ocean along the Petaluma Gap, through Bennett Valley, and into the northern end of the valley. This additional western entry point appears to have more influence on the fog we experience than San Pablo Bay, probably because we are more remote (15 miles) from the bay. However, we experience winds in equal measure from both the west and south, bringing cooling maritime influences to our vineyard, though by the time these winds have traveled across the valley floors, they have warmed considerably.

In essence, San Pablo Bay provides some cooling influence to Sonoma Mountain, but the mountain’s elevation and eastern slope orientation are more significant natural factors, creating the sheltered, sun-exposed, moderated microclimate that is ideal for ripening our Bordeaux varieties.