Resident Population in Westchester County, NY was 1006.44700 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Westchester County, NY reached a record high of 1006.44700 in January of 2024 and a record low of 865.69500 in January of 1982. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Westchester County, NY - last updated from the United States Federal Reserve on April of 2026.