Paso Robles is a sprawling AVA in San Luis Obispo County on California's Central Coast, encompassing over 40,000 vineyard acres across 11 sub-districts.
The region's defining feature is an extreme diurnal temperature variation — often exceeding 50°F (28°C) between day and night — which preserves acidity while allowing full phenolic ripeness.
Rhone varieties (Grenache, Syrah, Mourvèdre) and Zinfandel have become signatures, though Cabernet Sauvignon dominates plantings.
The western Adelaida District, with its calcareous soils and coastal influence, produces particularly structured wines.
Notable producers include Tablas Creek, Justin, Daou, and Epoch.