Vineyards in Colorado are mostly nestled in the temperate, high elevation river valleys and mesas of Mesa and Delta counties, with some acreage in Montezuma county. Colorado’s grape growing regions range in elevation from 4,000 to 7,000 feet and are thus among the highest vineyards in the world, resulting in hot days accompanied by cool nights.
The ‘continental climate’ in these regions create day to night temperature variations topically ranging from 25 to 30 degrees during the grape maturation months of August and September. The long warm daylight hours of intense high-altitude sunlight mature the fruit completely and build the natural sugars. The cool evenings cause the grapes to retain the acids so vital to premium winemaking. However, the high altitude can also present a challenge to grape growers, in that the average frost free growing season ranges from 150 to 182 days.
Read Wall Street Jouranl article on young winemakers: https://www.wsj.com/articles/the-wines-to-buy-this-thanksgiving-a-guide-to-americas-up-and-coming-regions-11573836307