Greater Boston
Combined Statistical Area
Boston in July 2015
Interactive Map of Boston–Worcester–Providence, MA–RI–NH CSA   City of Boston Boston–Cambridge–Newton, MA–NH MSA   Boston, MA Metropolitan Division   Cambridge–Newton–Framingham, MA   Rockingham County–Strafford County, NH Other Statistical Areas in Boston CSA   Providence–Warwick, RI–MA MSA   Worcester, MA MSA   Manchester–Nashua, NH MSA   Barnstable Town, MA MSA   Concord, NH µSA   Laconia, NH µSA
Country	United States
State	Massachusetts Rhode Island New Hampshire
Principal cities	Boston Worcester Providence Cambridge Manchester Lowell Brockton  Quincy Lynn New Bedford
Population  (2020)
• Total	8,466,186 (CSA) 4,941,632 (MSA)
• Rank	Ranked 6th in the US for Combined Statistical Areas Ranked 10th in the US for Metropolitan Statistical Areas
GDP [1]
• Boston (MSA)	$571.7 billion (2022)
Time zone	UTC−5 (EST)
• Summer (DST)	UTC−4 (EDT)
Area code(s)	617, 781, 857, 339, 978, 508, 351, 774, 603, 401

Greater Boston is the metropolitan region of New England encompassing the municipality of Boston, the capital of the U.S. state of Massachusetts and the most populous city in New England, and its surrounding areas. The most stringent definition of the region consists of most of the eastern third of mainland Massachusetts, excluding the Merrimack Valley and most of Southeastern Massachusetts, though most definitions (including the US Census definition) include much of these areas and portions of southern New Hampshire.^[2]

While the city of Boston covers 48.4 square miles (125 km²) and has 675,647 residents as of the 2020 census, the urbanization has extended well into surrounding areas and the Combined Statistical Area (CSA in the rest of the document), which includes the Providence, Rhode Island, Manchester, New Hampshire, Cape Cod and Worcester areas, has a population of more than 8.4 million people, making it one of the most populous such regions in the U.S.

Some of Greater Boston's most well-known contributions involve the region's higher education and medical institutions. Greater Boston has been influential upon American history and industry. The region and the state of Massachusetts are global leaders in biotechnology, artificial intelligence,^[2] engineering, higher education, finance, and maritime trade.^[3]

Greater Boston is ranked tenth in population among US metropolitan statistical areas, home to 4,941,632 people as of the 2020 United States Census, and sixth among combined statistical areas, with a population of 8,466,186. The area has hosted many people and sites significant to American culture and history, particularly American literature,^[4] politics, and the American Revolution.

Plymouth was the site of the first colony in New England, founded in 1620 by the Pilgrims, passengers of the Mayflower. In 1692, the town of Salem and surrounding areas experienced one of America's most infamous cases of mass hysteria, the Salem witch trials.^[5] In the late 18th century, Boston became known as the "Cradle of Liberty"^[6] for the agitation there that led to the American Revolution.

The Greater Boston region has played a powerful scientific, commercial, and cultural role in the history of the United States. Before the American Civil War, the region was a center for the abolitionist, temperance,^[7] and transcendentalist^[8] movements.^[9] In 2004, Massachusetts became the first U.S. state to legally recognize same-sex marriage as a result of the decision of the Massachusetts Supreme Judicial Court in Boston.^[10] Many prominent American political dynasties have hailed from the Boston region, including the Adams and Kennedy families.

Harvard University in Cambridge is the oldest institution of higher learning in the United States,^[11] with the largest financial endowment of any university,^[12] and whose Law School has spawned a contemporaneous majority of United States Supreme Court Justices.^[13] Kendall Square in Cambridge has been called "the most innovative square mile on the planet", in reference to the high concentration of entrepreneurial start-ups and quality of innovation which have emerged in the vicinity of the square since 2010.^[14][15] Both Harvard University and the Massachusetts Institute of Technology, also in Cambridge, have been ranked among the most highly regarded academic institutions in the world.^[16]

Geography

Boundary definitions

Metropolitan Area

The most restrictive definition of the Greater Boston area is the region administered by the Metropolitan Area Planning Council.^[17] The MAPC is a regional planning organization created by the Massachusetts legislature to oversee transportation infrastructure and economic development concerns in the Boston area. The MAPC includes 101 cities and towns that are grouped into eight subregions. These include most of the area within the region's outer circumferential highway, I-495. In 2013, the population of the MAPC district was 3.2 million, which was 48% of the total population of Massachusetts,^[18] in an area of 1,422 square miles (3,680 km²),^[17] of which 39% is forested and an additional 11% is water, wetland, or other open space.^[19]

The cities and towns included in this definitions are:^[20]

Metropolitan Area

Two definitions are used by the United States Census to define the Boston–Cambridge–Newton, MA–NH Metro Area or Boston–Cambridge–Newton, MA–NH Metropolitan NECTA, which is defined as a New England City and Town Area.^[21][22] The metro area definition is based on counties, while the NECTA definition is based on city and town boundaries. Counties included in the county-based definition include:^[21]

• Essex County, Massachusetts
• Middlesex County, Massachusetts
• Norfolk County, Massachusetts
• Plymouth County, Massachusetts
• Suffolk County, Massachusetts
• Rockingham County, New Hampshire
• Strafford County, New Hampshire

The NECTA definition includes all of the communities from the MAPC definition, as well as the Merrimack Valley communities, parts of southern New Hampshire (northward to Milford and Hampton, and the Taunton area.

Combined Statistical Area

The widest definition of the metropolitan area based on commuting patterns, is defined by the U.S. Census as the Boston–Worcester–Providence combined statistical area. This area consists of the following counties in Connecticut, Massachusetts, Rhode Island, and New Hampshire:^[23]

• Connecticut
  • Windham County, Connecticut
• Massachusetts
  • Barnstable County, Massachusetts
  • Bristol County, Massachusetts
  • Essex County, Massachusetts
  • Middlesex County, Massachusetts
  • Norfolk County, Massachusetts
  • Plymouth County, Massachusetts
  • Suffolk County, Massachusetts
  • Worcester County, Massachusetts
• New Hampshire
  • Belknap County, New Hampshire
  • Hillsborough County, New Hampshire
  • Merrimack County, New Hampshire
  • Rockingham County, New Hampshire
  • Strafford County, New Hampshire
• Rhode Island
  • Bristol County, Rhode Island
  • Kent County, Rhode Island
  • Newport County, Rhode Island
  • Providence County, Rhode Island
  • Washington County, Rhode Island

The total population for the extended region was estimated at 8,466,186 at the 2020 census.^{[citation needed]}

Subregions

• Massachusetts
  • Central Massachusetts
    • Montachusett-North County
    • South County
    • Blackstone River Valley
    • North Shore
    • Cape Ann
  • Merrimack Valley
  • MetroWest
  • Southeastern Massachusetts
    • Cape Cod
  • South Coast
  • South Shore
• New Hampshire
  • Lakes Region
  • Seacoast
• Rhode Island
  • Blackstone Valley
  • East Bay

Climate

The Boston area has humid continental climates (Dfa and Dfb under the Köppen climate classification system), with high humidity and precipitation year-round.