While California has more than 80 AVAs, some of them so small they are scarcely more than single vineyards, the vast North Coast region must be weighed on a different scale. This all encompassing appellation takes in all the counties north of San Francisco: Lake, Marin, Mendocino, Napa, Sonoma, and Solano. Despite its gargantuan size of over three million acres, the North Coast AVA is generally influenced by a couple of key ecological factors, with the most significant climatic feature being the cool coastal air and fog from the Pacific Ocean. This creates temperatures that are consistently cooler with higher annual rainfall than in the hot and dry Central Valley. These are the conditions that favor production of premium grapes, like Cabernet Sauvignon, Cabernet Franc, Pinot Noir, Merlot, Chardonnay, and Sauvignon Blanc. Ecology aside, the primary utility of "North Coast", as an AVA, is projecting a premium image in the marketing of high volume varietal brands, necessarily sourced and blended from far-flung vineyards.