Resident Population in Des Moines County, IA was 38.41100 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Des Moines County, IA reached a record high of 46.98200 in January of 1970 and a record low of 38.25800 in January of 2022. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Des Moines County, IA - last updated from the United States Federal Reserve on April of 2026.