Greendale is located in St. louis county Missouri with a geographic area of 0.2 square miles. The total population in Greendale is 847 with 35.2% male and 64.8% female. Children under age 5 represent 16.6% of the population, under age 18 equal 27.5% of the population and over age 65 is 24.9% of the population. The median household income is $42,228, per capita income is $27,499. There are a total of 401 housing units with 81.5% owner occupied. Education includes 27.7% of residents that are high school graduates and 35.9% with a bachelor's degree or higher. The average temperature in Greendale in the summer is 77 degrees, and in the winter 32 degrees.