Resident Population in Whatcom County, WA was 231.91900 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Whatcom County, WA reached a record high of 231.91900 in January of 2023 and a record low of 81.98300 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Whatcom County, WA - last updated from the United States Federal Reserve on May of 2024.