Resident Population in Madison County, IA was 16.97100 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Madison County, IA reached a record high of 17.03600 in January of 2022 and a record low of 11.55800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Madison County, IA - last updated from the United States Federal Reserve on May of 2024.