Mount Ayr, IA has a population of 1,958 and is the 11,147th largest city in the United States. The population density is 737 per sq mi which is 1249% higher than the Iowa average and 714% higher than the national average. The median age in Mount Ayr is 50 which is approximately 32% higher than the Iowa average of 38. In Mount Ayr, 68% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 73% of Mount Ayr residents were born in Iowa, 25% were born out of state, 0% were born outside of the United States and 1% were foreign born.