Population Estimate, Total, Not Hispanic or Latino, White Alone (5-year estimate) in Merrimack County, NH was 140561.00000 Persons in January of 2024, according to the United States Federal Reserve. Historically, Population Estimate, Total, Not Hispanic or Latino, White Alone (5-year estimate) in Merrimack County, NH reached a record high of 141025.00000 in January of 2009 and a record low of 137700.00000 in January of 2014. Trading Economics provides the current actual value, an historical data chart and related indicators for Population Estimate, Total, Not Hispanic or Latino, White Alone (5-year estimate) in Merrimack County, NH - last updated from the United States Federal Reserve on April of 2026.