Darien is located in Fairfield county Connecticut with a geographic area of square miles. The total population in Darien is 21,752 with 49.2% male and 50.8% female. Children under age 5 represent 6.4% of the population, under age 18 equal 32.0% of the population and over age 65 is 13.6% of the population. The median household income is $243,750, per capita income is $129,829. There are a total of 6,945 housing units with 85.7% owner occupied. Education includes 3.7% of residents that are high school graduates and 87.0% with a bachelor's degree or higher. The average temperature in Darien in the summer is 68 degrees, and in the winter 27 degrees.