Why does the fog matter?
Cool marine air and fog can slow morning warming in parts of the valley. Sites above or beyond that influence may experience a very different temperature pattern.
Wine Atlas
United States
Napa Valley
A compact region where fog, bay influence, mountains, valley floor and elevation create several climates within a small area.
Why this place is interesting
Napa is a good demonstration of scale. Two vineyards can be geographically close but sit at different heights or on opposite sides of the fog line, giving the vines quite different daily temperatures.
Climate
Warm overall but strongly modified by cool marine air, fog, elevation and topography.
Terrain
A valley framed by mountain ranges, with vineyard sites from the valley floor to elevated slopes.
Soils & geology
Exceptionally varied, including volcanic, alluvial and sedimentary materials.
Worth remembering: geology can change how a vineyard drains, stores water and supports roots. It does not give us a reliable one-to-one flavour map.
Typical styles
Full redDry white
Questions worth asking
Do mountain wines automatically taste different?
Elevation, exposure, soil depth and water availability can all change together on mountain sites. It is the combination, not the word “mountain”, that matters.
Change the region, keep the country.
One of the cleanest ways to see why national wine stereotypes are so unreliable.