Mount union is located in Henry county Iowa with a geographic area of 0.2 square miles. The total population in Mount union is 135 with 54.1% male and 45.9% female. Children under age 5 represent 11.1% of the population, under age 18 equal 36.3% of the population and over age 65 is 6.7% of the population. The median household income is $50,000, per capita income is $19,325. There are a total of 54 housing units with 88.9% owner occupied. Education includes 22.2% of residents that are high school graduates and 7.4% with a bachelor's degree or higher. The average temperature in Mount union in the summer is 72 degrees, and in the winter 23 degrees.