Auburn is a town in Rockingham County, New Hampshire, United States. The population was 4,953 at the 2010 census, with an estimated population of 5,449 in 2017.
According to the United States Census Bureau, the town has a total area of 28.7 square miles (74.3 km), of which 25.2 sq mi (65.3 km) is land and 3.5 sq mi (9.1 km), or 12.20%, is water. Massabesic Lake, located in the western part of Auburn and the eastern part of Manchester, is the largest body of water in Auburn and serves as the city water supply for Manchester. The lake is fed by numerous tributaries, most notable being Sucker Brook, which enters the northeast end of the lake near the Auburn town center and itself drains several lakes, including Tower Hill Pond, Clark Pond, and Little Massabesic Lake. Cohas Brook flows through the eastern portion of Auburn and eventually (in Manchester) receives the outflow of Massabesic Lake before flowing west to the Merrimack River. Auburn lies fully within the Merrimack River watershed. Three hills, all overlooking Massabesic Lake, can lay potential claim to being Auburn’s highest point: Mount Miner, at 582 feet (177 m) above sea level, located north of the lake; Mine Hill, greater than 580 ft (180 m), above the east shore; and Mount Misery, greater than 580 feet, to the southeast.
As of the census of 2000, there were 4,682 people, 1,580 households, and 1,322 families residing in the town. The population density was 185.7 people per square mile (71.7/km²). There were 1,622 housing units at an average density of 64.3 per square mile (24.8/km²). The racial makeup of the town was 98.29% White, 0.21% African American, 0.23% Native American, 0.41% Asian, 0.23% from other races, and 0.62% from two or more races. Hispanic or Latino of any race were 0.94% of the population.
There were 2,349 households out of which 44.4% had children under the age of 18 living with them, 75.1% were married couples living together, 5.2% had a female householder with no husband present, and 16.3% were non-families. 11.8% of all households were made up of individuals and 3.3% had someone living alone who was 65 years of age or older. The average household size was 2.96 and the average family size was 3.22.
In the town, the population was spread out with 28.9% under the age of 18, 6.2% from 18 to 24, 33.0% from 25 to 44, 25.8% from 45 to 64, and 6.1% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 103.6 males. For every 100 females age 18 and over, there were 103.2 males.
The median income for a household in the town was $70,774, and the median income for a family was $72,578. Males had a median income of $45,000 versus $33,365 for females. The per capita income for the town was $28,405. About 1.6% of families and 1.8% of the population were below the poverty line, including 0.7% of those under age 18 and 11.2% of those age 65 or over.
Since Auburn has an agreement with the city of Manchester that the city and the surrounding towns can use Massabesic Lake as a water source, Manchester, Chester, Candia, Hooksett and Derry pay Auburn an estimated $3 million for Lake Massabesic.