Nicasio, CA has a population of 113 and is the 26,604th largest city in the United States. The population density is 87 per sq mi which is 63% lower than the California average and 4% lower than the national average. The median age in Nicasio is 40 which is approximately 12% higher than the California average of 36. In Nicasio, 60% of the population over 15 years of age are married, 72% speak English and 19% speak Spanish. 81% of Nicasio residents were born in California, 9% were born out of state, 0% were born outside of the United States and 10% were foreign born.