The Sonoma County appellation is California’s most extreme climate thanks to the Pacific fog and strong winds that flow through the Petaluma Wind Gap, a break in the jagged mountains at Bodega Bay. A single day might see a temperature flux of 50 degrees Fahrenheit. Enveloping morning fog gives way to late morning sun warming the vines and prompting an ideal dose of photosynthesis before the cool afternoon breezes usher nightly fog.