Penngrove, CA has a population of 2,940 and is the 8,912th largest city in the United States. The population density is 731 per sq mi which is 214% higher than the California average and 706% higher than the national average. The median age in Penngrove is 44 which is approximately 22% higher than the California average of 36. In Penngrove, 61% of the population over 15 years of age are married, 76% speak English and 19% speak Spanish. 73% of Penngrove residents were born in California, 17% were born out of state, 0% were born outside of the United States and 10% were foreign born.