
Northumberland
- County:
- Coos County
- County Seat:
- No
- Area (mi²):
- 35.689
- State:
- New Hampshire
Northumberland is located in Coos County, New Hampshire. Northumberland has a 2025 population of 2,084. Northumberland is currently declining at a rate of -0.81% annually and its population has decreased by -1.98% since the most recent census, which recorded a population of 2,126 in 2020.
The average household income in Northumberland is $64,356 with a poverty rate of 17.42%. The median age in Northumberland is 48 years: 49.5 years for males, and 45.3 years for females.