The proximity of the Pacific Ocean, orientation of numerous canyons and valleys, and varying elevations produce many different distinct microclimates in the Paso Robles AVA.

The area benefits from the largest swing between high daytime and low nighttime temperatures of any region in California as a result of the cool marine air that flows east through the Templeton Gap and south along the Salinas River Valley from the Monterey Bay. The region’s summer is characterized by warm, clear days, generally unencumbered by clouds, fog or severe winds. Daytime high temperatures in the summer typically fall between 85 and 105 degrees Fahrenheit, but nighttime low temperatures usually can drop by 40 to 50 degrees, cooled by a marine layer that moves over the region in the mid to late afternoon. This fluctuation is considered a key by winemakers and wine grape growers to attain the intense varietal character displayed in wine grapes from the area.

September, October and the first half of November are typically rain-free and warm, giving Paso Robles vines the advantage of time to produce fully mature fruit, while the overnight cooling keeps the grapes’ acid chemistry in balance. The first rainfall of the season is typically about two weeks later than Napa or Sonoma, and a month later than Mendocino, giving winemakers the luxury of waiting for optimal ripeness. Winter temperatures tend to dip into the low twenties in the cooler regions, with most vineyards becoming fully dormant by mid-December. Frost is also a potential threat through mid-May, especially following a northern weather system.

For more information, visit the Paso Robles Wine Country Alliance at www.pasowine.com.