Migration into the state generated all statewide population growth between April 2020 and July 2023. However, increases due to migration differed by county. Hillsborough County was the only county to experience a net migration loss to other parts of the United States during this time; however, the county also experienced the largest net international migration, and was the only county to have more births than deaths among its residents. Rockingham County and Merrimack County, two other populous southeastern counties, experienced the largest net increase in the number of people migrating into the county between 2020 and 2023; Coos County and Sullivan County experienced the smallest net increase from migration. 

Learn more in NHFPI’s August 2024 issue brief: New Hampshire’s Growing Population and Changing Demographics Before and Since the COVID-19 Pandemic