Temecula Valley AVA | American Viticultural Area in California. The AVA dates from 1984 and is located in the south-western part of Riverside County, 60 miles north of San Diego and 90 miles southeast of Los Angeles, near the borders of Riverside and San Diego Counties but entirely within Riverside County, and within the blanket South Coast AVA of Southern California. The AVA takes its name from the town of Temecula