Plymouth is located in Litchfield county Connecticut with a geographic area of square miles. The total population in Plymouth is 11,646 with 47.1% male and 52.9% female. Children under age 5 represent 3.8% of the population, under age 18 equal 18.1% of the population and over age 65 is 17.3% of the population. The median household income is $79,029, per capita income is $40,527. There are a total of 4,861 housing units with 76.7% owner occupied. Education includes 34.8% of residents that are high school graduates and 23.0% with a bachelor's degree or higher. The average temperature in Plymouth in the summer is 68 degrees, and in the winter 27 degrees.