Resident Population in Windham County, CT was 116.41800 Thous. of Persons in January of 2021, according to the United States Federal Reserve. Historically, Resident Population in Windham County, CT reached a record high of 118.54300 in January of 2010 and a record low of 84.51500 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Windham County, CT - last updated from the United States Federal Reserve on September of 2025.