Which valley is noted for being the hottest among Sonoma County AVAs?

Knight's Valley is recognized as the hottest among Sonoma County AVAs, primarily due to its unique geographic and climatic conditions. This valley lies at the northern edge of Sonoma County, situated between the Mayacamas Mountains and the Sonoma Mountains. The topography creates a funneling effect that allows warm air to accumulate, leading to higher temperatures compared to other nearby regions.

The warmth in Knight's Valley contributes to its ability to produce rich, ripe grapes, particularly varietals like Cabernet Sauvignon and Zinfandel, which thrive in warmer climates. The combination of warm days and cooler nights allows for a balance of sugar development and acidity, which is ideal for winemaking.

In contrast, the other valleys mentioned have their distinct climates but do not reach the same temperature extremes as Knight's Valley. For example, the Monterey Bay has a more maritime influence with cooler temperatures due to ocean breezes, while the Santa Lucia Highlands is known for cooler weather influenced by marine layers. Chalone, while primarily focused on Chardonnay and Pinot Noir, does not share the extreme heat that characterizes Knight's Valley.