Greater Boston

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, health care, engineering, higher education, finance, and maritime trade.

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 seventh among combined statistical areas, with a population of 8,493,824. The area has hosted many people and sites significant to American culture and history, particularly American literature, 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. In the late 18th century, Boston became known as the "Cradle of Liberty" 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, and transcendentalist movements. 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. 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, founded in 1636, with the largest financial endowment of any university, and whose Law School has spawned a contemporaneous majority of United States Supreme Court justices. 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. 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.

Geography

Boundary definitions

Metropolitan Area

The most restrictive definition of the Greater Boston area is the region administered by the Metropolitan Area Planning Council. 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, in an area of 1,422 square miles (3,680 km²), of which 39% is forested and an additional 11% is water, wetland, or other open space.

The cities and towns included in this definition are:

• Acton
• Arlington
• Ashland
• Bedford
• Bellingham
• Belmont
• Beverly
• Bolton
• Boston
• Boxborough
• Braintree
• Brookline
• Burlington
• Cambridge
• Canton
• Carlisle
• Chelsea
• Cohasset
• Concord
• Danvers
• Dedham
• Dover
• Duxbury
• Essex
• Everett
• Foxborough
• Framingham
• Franklin
• Gloucester
• Hamilton
• Hanover
• Hingham
• Holbrook
• Holliston
• Hopkinton
• Hudson
• Hull
• Ipswich
• Lexington
• Lincoln
• Littleton
• Lynn
• Lynnfield
• Malden
• Manchester-by-the-Sea
• Marblehead
• Marlborough
• Marshfield
• Maynard
• Medfield
• Medford
• Medway
• Melrose
• Middleton
• Milford
• Millis
• Milton
• Nahant
• Natick
• Needham
• Newton
• Norfolk
• North Reading
• Norwell
• Norwood
• Peabody
• Pembroke
• Quincy
• Randolph
• Reading
• Revere
• Rockland
• Rockport
• Salem
• Saugus
• Scituate
• Sharon
• Sherborn
• Somerville
• Southborough
• Stoneham
• Stoughton
• Stow
• Sudbury
• Swampscott
• Topsfield
• Wakefield
• Walpole
• Waltham
• Watertown
• Wayland
• Wellesley
• Wenham
• Weston
• Westwood
• Weymouth
• Wilmington
• Winchester
• Winthrop
• Woburn
• Wrentham

New England City and Town 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. 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:

• 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 Massachusetts, Rhode Island, and New Hampshire:

• 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 7,493,824 at the 2020 census.

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

Most of the Boston area has humid subtropical climates (Cfa under the Köppen climate classification system), with high humidity and precipitation year-round. The northwestern regions near New Hampshire and Worcester have humid continental Dfa and Dfb conditions due to January means being below −3 °C (27 °F) and July means below 22 °C (72 °F).