Sonoma runs more or less parallel with Napa but much closer to the coast, which for much of the valley and areas like Green and Russian River in particular means cool climate and a long growing season. For instance our growers at Freeman routinely harvest in October, fully a month after their peers in Burgundy. It is the cold coastal Pacific currents that cause that. Additionally if you are visiting northern California, Sonoma is a little more real and less touristy. (CW 23/01/12)