Estimate, Median Age by Sex, Total Population (5-year estimate) in Island County, WA was 44.20000 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 Island County, WA reached a record high of 44.30000 in January of 2016 and a record low of 42.40000 in January of 2010. 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 Island County, WA - last updated from the United States Federal Reserve on May of 2024.