Census Data for Watertown

Population ...

The last Decennial Census<1> was in 2010, which gave Watertown a population of 31,915 people.

The city of Watertown is located in Middlesex County. The 2010 Census gave Middlesex County; a population of 1,507,681 people. This means that Watertown had 2.12% of the county's total population, making it Middlesex's 16th most populous community.

At the same time, Massachusetts had a population of 6,547,629 people, meaning that Watertown had 0.49% of the total population of Massachusetts - making it the state's 51st most populous community.

Area ...

The 2010 Census shows that the sampling area for Watertown has a total area of 4.12 square miles [10.7 km²]. Of this total, 3.99 square miles [10.3 km²] is land, with the balance (2.99%) being water (0.12 square miles [0.3 km²]).

Middlesex County has a land area of 817 square miles [2,118.1 km²]. At 3.99 square miles [10.3 km²], Watertown has 0.49% of the county's total land area.

• Continue Reading ...
  • When the Census Bureau conducts a census for a city like Watertown, they draw a boundary around the area in which they are going to conduct their count - this defines the sampling area (usually a polygon). The shape of the sampling area can be quite complex and it's important to keep in mind that the boundaries of the sampling area may or may not match the recognized boundaries of the city.
  • Things like population, area and housing for Watertown reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Watertown might be different, it's best to check with the U.S. Census Bureau to resolve any difference between the two.
  • Not only does the sampling area define boundaries, it also has a GPS location (latitude & longitude) that indicates a point within the sampling area (usually the center of the polygon, known as the centroid). At the time of the 2010 Census, the sampling area was located at:
  • Lat:   42° 22' 10"   (or 42.37°)
  • Lon:   -71° 10' 40"   (or -71.18°)

Housing Units ...

At the time of the 2010 Census, Watertown had 15,584 Housing Units<2> and with its population of 31,915 people, this averages 2.05 people per Housing Unit.

• Continue Reading ...
  • The 2010 Census shows Watertown had a land area of 3.99 square miles [10.3 km²]. This translates to 3,786 Housing Units per square mile [1,461 housing units/km²].

Middlesex County ...

Watertown is located in Middlesex County<3>.

The county had a population of 1,507,681 people at the 2010 Census. With it's population of 31,915 people, Watertown represented 2.12% of the county's total.

In addition, where the city of Watertown has a population density of 7,753 people per square mile [2,993 people/km²], Middlesex County averages 1,843 people per square mile [711 people/km²].

For more information, please visit our Census Page for Middlesex County.

Census-to-Census Observations ...

Introduction ...

When the Census Bureau takes a census count (or enumeration) for Watertown, they start by specifying the boundaries of the area to be counted. This area (or sampling area) is a polygon and its shape can be quite complex - it may or may not match the geographical boundaries of Watertown. It's important to note that from one Census to the next, the shape and location of the polygon can change.

• Continue Reading ...
  • Although we don't have specific information about the shape of the polygon for Watertown or how it changed has over time, there is some information that can give us some hints. For example, since the shape of the sampling area is directly related to the shape of the polygon, any change to area probably indicates a new shape for the polygon.
  • If you need precision or details about the methodology of the Census, you should visit the U.S. Census Bureau for a definitive answer.

Location ...

While generally coinciding with the GPS location (latitude/longitude) of Watertown, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Watertown.

• Continue Reading ...
  • For the 2010 Censuses, the location was given as:

  Lat:   42.369451°   (or 42°22'10" N)

  Lon:   -71.177925°   (or -71°10'40" W)

  • The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#618242) to Watertown. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Watertown. The GNIS point has been mapped to the latitude/longitude:
  • Lat:   42.366763°   (or 42°22'0" N)
  • Lon:   -71.166165°   (or -71°9'58" W)
  • The GPS location given for the 2010 Census lies 3,315 feet to the west<4> of the point given by the GNIS for Watertown. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Watertown.

Miscellaneous Information for Watertown ...

The Federal government has assigned various identifying codes to each community, county and state. At one time or another, the US Census Bureau has used one (or more) of the following identifiers when referring to either Middlesex County or the city of Watertown:

• The GNIS Codes ...
  • The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to Watertown:
  • GNIS ID for Watertown: 618242
  • GNIS ID for Middlesex County: 606935
  • GNIS ID for State of Massachusetts: 606926

• The FIPS Codes ...
  • An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
  • State Code: 25 (Massachusetts)
  • County Code: 017 (Middlesex County)
  • Place Code: 73405 (Watertown)
  • State & County Code: 25/017 (Massachusetts / Middlesex County)
  • State & Place Code: 25/73405 (Massachusetts / Watertown)

• Misc. Census Codes ...
  • Watertown is located in Census Region #1 (the Northeast Region) and Division #1 (the New England Division).

• The US Postal Service ZIP Code ...
  • While some people have used ZIP codes to identify a community, the ZIP codes were actually created to make mail delivery more efficient by grouping addresses together. Although a ZIP Code doesn't specifically identify a city like Watertown, they do identify addresses that are in (or near) the city. It's important to remember that the boundaries of the ZIP Code can be changed, re-assigned, eliminated or overlapped with other ZIP Codes.
  • Our list of ZIP codes for Watertown:<5>
  • 02471 & 02472.

• Census ZCTA Codes ...
  • The US Census Bureau created statistical entities that they call ZIP Code Tabulation Areas (ZCTAs) and these ZCTAs are frequently confused with the ZIP codes that come from the US Postal Service (USPS).
  • ZCTAs were first created for the 2000 Census and at that time, they were based upon the USPS ZIP codes. While largely covering the same areas, the boundaries of a ZCTA do not necessarily match the boundaries of a postal ZIP code with the same number. For example, while a postal ZIP code can cross a county or state line, a Census ZCTA can not. They should be treated as separate entities with no correlation between them.

For more information about the various Federal identification codes, please visit our Misc Page for Watertown.

Off-the-Road Links ...

Unfortunately, we don't know of a website for Watertown. If you can help, please contact us through our Feedback Page.

The official website for State of Massachusetts: https://www.mass.gov/

The official website of the U.S. Census Bureau

The official website of the U.S. Board on Geographic Names (BGN)

The official website of the U.S. Geological Survey (USGS)