According to the United States Census Bureau, the town has a total area of, of which are land and, or 2.09%, are water. The highest point in Pelham is Jeremy Hill, at above sea level. The town contains the southernmost point in the state of New Hampshire, at, a location known as the "Old Boundary Pine", named for a pine tree that marked the difference in definition of the northern boundary of Massachusetts. This point is due north of Pawtucket Falls in Lowell, and marks the point where the straight-line border to the west meets the 3-mile buffer defined by the Merrimack River. In addition to being New Hampshire's southernmost town, Pelham is the easternmost town in Hillsborough County.
The earliest census data shows the town of Pelham having a population of 543 residents in 1767. As of the census of 2000, there were 10,914 people, 3,606 households, and 2,982 families residing in the town. The population density was 412.9 people per square mile. There were 3,740 housing units at an average density of 141.5 per square mile. The racial makeup of the town was:
Hispanic or Latino of any race were 0.96% of the population. In 2000, there were 3,606 households, with an average household size of 3.03 and an average family size of 3.33.
43.6% of households had children under the age of 18 living with them.
7.5% had a female householder with no husband present.
17.3% were non-families.
12.9% of all households were made up of individuals.
5.7% had someone living alone who was 65 years of age or older.
In 2000, the town's population had a median age of 36 years.
28.9% under the age of 18
6.1% from 18 to 24
34.0% from 25 to 44
23.2% from 45 to 64
7.8% who were 65 years of age or older
For every 100 females, there were 98.8 males. For every 100 females age 18 and over, there were 99.3 males. The median income for a household in the town was $68,608.. The median income for a family was $73,365.. Males had a median income of $47,685 versus $33,375 for females. The per capita income for the town was $25,158. About 1.6% of families and 3.0% of the population were below the poverty line, including 3.1% of those under age 18 and 4.7% of those age 65 or over.
Education
Public schools are managed by the Pelham School District, part of School Administrative Unit #28, whose boundaries are coterminous with the boundaries of the town. The Superintendent is William Furbush. The schools in the district are:
St. Patrick School was at one time a parochial school in the town.
Pelham government
Pelham is governed by a board of selectmen:
William McDevitt, Chair
Douglas Viger, Vice-Chair
Harold Lynde
Kevin Cote
Heather Forde
Transportation
Pelham is crossed by three New Hampshire state routes:
NH 38 enters the town from the south at the Massachusetts border, and curves to the northeast, exiting the town into Salem. It follows Bridge Street through town, and serves as the commercial hub of Pelham.
NH 111A begins at a junction with NH 128 just north of the Massachusetts border, going primarily northeast, exiting the town into Windham. It is known as Marsh Road and Windham Road within Pelham.
NH 128 is part of the larger Mammoth Road which connects Lowell, Massachusetts to Hooksett, New Hampshire. It enters the town from Massachusetts border, and goes due north, along the western edge of the town, before exiting the town into Windham.
The closest Interstate highway is Interstate 93, which is accessed northeast of the center of Pelham in neighboring Salem. Pelham appears on that highway's signs for Exit 2. The U.S. Route 3 freeway that runs through Nashua is west of the center of Pelham, and Interstate 495 in Massachusetts is south of Pelham, on the south side of Lowell. Pelham has no air or rail transport within the town limits. The nearest commercial airport is Manchester–Boston Regional Airport along the border of Londonderry and Manchester. The nearest rail service is the Lowell Line of the MBTA Commuter Rail which can be accessed at the Charles A. Gallagher Transit Terminal in Lowell, Massachusetts. The nearest Amtrak station is Haverhill Station in Haverhill, Massachusetts.
Parks
Muldoon Park
The park is located northwest of the center of Pelham at 305 Mammoth Road, just north of Nashua Road. The park's land area is surrounded by NH 128, two roads that branch off it, and a minor road which intersects NH 111A. Muldoon Park offers many short walking trails, four variously sized baseball fields, a soccer field, and a play area. Most of the trails lead to the park's two ponds, local roads and houses or to Beaver Brook, a small river. The town of Pelham completed an 18-hole disc golf course here, stretching over a quarter-mile, in September 2007. The Pelham Parks and Recreation department has recently added two non-official sized baseball fields to the southwest corner of the park. Construction is complete on one field with the exception of dugouts, and the other field is still under construction, as of September 2013. There is now an 18-hole disc golf course at this park. Many players from surrounding towns enjoy a round of disc golf set in the woods adjacent to the sport fields.