COUNTY · NH
Merrimack County, New Hampshire
Merrimack County is a county in New Hampshire with FIPS code 33013 and an estimated population of 157,103 (Census 2023), 3rd largest of 10 in the state.
County facts
- Name
- Merrimack County
- State
- New Hampshire
- Type
- county
- FIPS code
- 33013
- State FIPS
- 33
- Population (2023)
- 157,103
- Change since 2020
- +2.0%
- State rank
- 3 of 10
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Merrimack County?
Merrimack County, New Hampshire has the five-digit FIPS code 33013: 33 for the state and 013 for the county.
What state is Merrimack County in?
Merrimack County is in New Hampshire.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.