Estimate, Median Age by Sex, Total Population (5-year estimate) in Dallas County, IA was 35.60000 Years of Age in January of 2022, according to the United States Federal Reserve. Historically, Estimate, Median Age by Sex, Total Population (5-year estimate) in Dallas County, IA reached a record high of 35.60000 in January of 2022 and a record low of 34.20000 in January of 2011. Trading Economics provides the current actual value, an historical data chart and related indicators for Estimate, Median Age by Sex, Total Population (5-year estimate) in Dallas County, IA - last updated from the United States Federal Reserve on May of 2024.