Union is located close to the center of Iowa. Union is between the Hardin, Grundy, Marshall county. Union has 0.55 square miles of land area and has no water area. As of 2010-2014, the total Union population is 522, which has grown 22.25% since 2000. The population growth rate is much higher than the state average rate of 5.19% and is much higher than the national average rate of 11.61%. Union median household income is $41,563 in 2010-2014 and has grown by 19.46% since 2000. The income growth rate is much lower than the state average rate of 33.56% and is lower than the national average rate of 27.36%. Union median house value is $63,200 in 2010-2014 and has grown by 37.09% since 2000. The house value growth rate is lower than the state average rate of 53.09% and is lower than the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers Union is much better than the state average in quality. The Union area code is 641.