Rio Dell, CA has a population of 3,372 and is the 8,229th largest city in the United States. The population density is 1,478 per sq mi which is 536% higher than the California average and 1532% higher than the national average. The median age in Rio Dell is 42 which is approximately 17% higher than the California average of 36. In Rio Dell, 56% of the population over 15 years of age are married, 93% speak English and 5% speak Spanish. 77% of Rio Dell residents were born in California, 20% were born out of state, 0% were born outside of the United States and 3% were foreign born.