Union is located in Montgomery county Ohio with a geographic area of 8.3 square miles. The total population in Union is 71 with 76.1% male and 23.9% female. Children under age 5 represent 0.0% of the population, under age 18 equal 47.9% of the population and over age 65 is 0.0% of the population. The median household income is $0, per capita income is $0. There are a total of 17 housing units with 100.0% owner occupied. Education includes 0.0% of residents that are high school graduates and 0.0% with a bachelor's degree or higher. The average temperature in Union in the summer is 71 degrees, and in the winter 27 degrees.