Nicasio is located in Marin county California with a geographic area of 1.3 square miles. The total population in Nicasio is 123 with 40.7% male and 59.3% female. Children under age 5 represent 0.8% of the population, under age 18 equal 28.5% of the population and over age 65 is 7.3% of the population. The median household income is $250,000, per capita income is $231,040. There are a total of 34 housing units with 94.1% owner occupied. Education includes 0.0% of residents that are high school graduates and 97.1% with a bachelor's degree or higher. The average temperature in Nicasio in the summer is 76 degrees, and in the winter 43 degrees.