Resident Population in Hardin County, IA was 16.46400 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Hardin County, IA reached a record high of 22.30000 in January of 1971 and a record low of 16.46400 in January of 2024. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Hardin County, IA - last updated from the United States Federal Reserve on April of 2026.