Livermore Valley AVA unique east-west orientation, unlike many other winegrowing valleys. Due to a reliable onshore afternoon/evening breeze off of the San Francisco Bay a wide fluctuation in temperature between sites and a large diurnal temperature swing occur. Livermore Valley is considered a Winkler Region III grape growing zone with temperatures comparable to northern Napa Valley appellations such as St. Helena or Calistoga. The relatively obscure Petite Sirah grape produced Livermore's best historically known red wine, although the climate also makes for interesting dessert wines as well as excellent Cabernet Sauvignon, Merlot and Rhone varieties. The original plantings of Sémillon and Sauvignon blanc
Creston District AVA acres with 1,365 planted in vineyards. It lies on an old erosional plateau at the base of the La Panza Range with alluvial terraces and fans of Huerhuero Creek. The area is in elevation. Average annual rainfall is . The district's soils consist of old, well developed terrace and hillside soils; mix of granite and sedimentary rock. The most widely planted varieties in the Creston District AVA are Cabernet Sauvignon, Syrah, Zinfandel, Merlot, Petite Sirah. Creston District AVA Creston District AVA is an American Viticultural Area located in the south east portion of the Paso Robles AVA in San Luis