Auburn, IA has a population of 302 and is the 22,477th largest city in the United States. The population density is 606 per sq mi which is 1010% higher than the Iowa average and 569% higher than the national average. The median age in Auburn is 40 which is approximately 6% higher than the Iowa average of 38. In Auburn, 63% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 77% of Auburn residents were born in Iowa, 21% were born out of state, 0% were born outside of the United States and 2% were foreign born.