Guerneville, CA has a population of 4,095 and is the 7,342nd largest city in the United States. The population density is 422 per sq mi which is 81% higher than the California average and 366% higher than the national average. The median age in Guerneville is 51 which is approximately 41% higher than the California average of 36. In Guerneville, 39% of the population over 15 years of age are married, 95% speak English and 3% speak Spanish. 59% of Guerneville residents were born in California, 36% were born out of state, 1% were born outside of the United States and 5% were foreign born.