Union is located in Boone county Kentucky with a geographic area of 3.5 square miles. The total population in Union is 5,988 with 51.2% male and 48.8% female. Children under age 5 represent 5.4% of the population, under age 18 equal 28.3% of the population and over age 65 is 12.3% of the population. The median household income is $123,630, per capita income is $42,709. There are a total of 1,835 housing units with 92.3% owner occupied. Education includes 20.4% of residents that are high school graduates and 58.3% with a bachelor's degree or higher. The average temperature in Union in the summer is 74 degrees, and in the winter 36 degrees.