St Helena Climate & Grape Growing
The Effect of St Helena Climate on Grape Growing
St Helena has a warmer climate than more southern regions in the Napa Valley. This is because the valley narrows hooks to the west through the region. What little wind and fog from the San Pablo Bay that makes it past the Yountville Mounts is largely dispersed by this phenomenon.
However, there is a cooling effect on the region’s climate. Throughout the Northern Napa Valley, warm afternoons draw cool air through the Chalk Hill and Knights Valley AVAs from the cooler Russian River Valley AVA. As evening temperatures drop, grapes are able to retain the acidity that is so critical for balance in warm viticultural areas.
St Helena receives more rainfall, 35-38 inches per year, than the southern valley, 25-32 inches per year. Vines can extend 400 feet up the valley walls and still be within the AVA’s boundaries.
Vineyard 29 is an exceptional property that takes advantage of St Helena’s favorable climate. Founded by Teresa Norton and Tom Paine in 1989, they planted their vineyard with cuttings from the neighboring Grace Family Vineyard.
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