Peterson, IA has a population of 300 and is the 22,505th largest city in the United States. The population density is 578 per sq mi which is 958% higher than the Iowa average and 538% higher than the national average. The median age in Peterson is 52 which is approximately 38% higher than the Iowa average of 38. In Peterson, 63% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 76% of Peterson residents were born in Iowa, 22% were born out of state, 0% were born outside of the United States and 2% were foreign born.