Ramona is a census-designated place in San Diego County, California. The population was 20,292 at the 2010 census.The term Ramona also refers to an unincorporated community that includes both the Ramona CDP and the adjacent CDP of San Diego Country Estates. The population of the two CDPs, which does not include the fringe areas surrounding the CDPs, was 30,301 at the 2010 census, up from 25,223 at the 2000 census. The Ramona Community Planning Area had a population of 33,404 at the 2000 census. The January 1, 2006, population of the Ramona Community Planning Area is estimated to be 36,405 by the San Diego Association of Governments. USDA Hardiness Zones are 9b and 10a.