Census Data for Mount Airy

Population ...

The most recent Census Estimate<1> was for 2019 and it gave Mount Airy a population of 9,489 people.

The last Decennial Census<2> was in 2010, which gave Mount Airy a population of 9,288 people.

The town of Mount Airy is located in Carroll County. The 2010 Census gave Carroll County; a population of 167,134 people. This means that Mount Airy had 5.56% of the county's total population, making it Carroll's 2nd most populous community.

At the same time, Maryland had a population of 5,773,552 people, meaning that Mount Airy had 0.16% of the total population of Maryland - making it the state's 23rd most populous community.

Area ...

The 2010 Census shows that the sampling area for Mount Airy has a total area of 4.13 square miles [10.7 km²]. Of this total, a small amount of the area is covered by water (0.01 square miles [0 km²]).

Carroll County has a land area of 447.6 square miles [1,159.3 km²]. At 4.12 square miles [10.7 km²], Mount Airy has 0.92% of the county's total land area.

• Continue Reading ...
  • When the Census Bureau conducts a census for a town like Mount Airy, 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 town.
  • Things like population, area and housing for Mount Airy reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Mount Airy 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:   39° 22' 27"   (or 39.37°)
  • Lon:   -77° 9' 12"   (or -77.15°)
  • More information on this topic and the changes between the 2000 Census and the 2010 Census can be found in the section for our Census-to-Census Observations ... (see below).

Housing Units ...

At the time of the 2010 Census, Mount Airy had 3,225 Housing Units<3> and with its population of 9,288 people, this averages 2.88 people per Housing Unit.

• Continue Reading ...
  • The 2010 Census shows Mount Airy had a land area of 4.12 square miles [10.7 km²]. This translates to 780 Housing Units per square mile [301.5 housing units/km²].
  • From the Census of 2000: Mount Airy had 2,179 Housing Units, a population of 6,425 people and a land area of 3.83 square miles [9.9 km²]. This gives a density of 2.95 people per Housing Unit and 569 Housing Units per square mile [219.8 housing units/km²].
  • Note: Repeating the caution above (under Population Density), be aware that when comparing Housing Units between the 2010 and the 2000 Census, there were changes in the sampling area for Mount Airy and you need to be careful when comparing between the censuses. More information about these differences can be found in the section called Census-to-Census Observations ... (see below).

Carroll County ...

The community of Mount Airy is primarily located in Carroll County<4>. A portion of Mount Airy extends into Frederick County.

The county had a population of 167,134 people at the 2010 Census. With it's population of 9,288 people, Mount Airy represented 5.56% of the county's total.

In addition, where the town of Mount Airy has a population density of 2,248 people per square mile [868 people/km²], Carroll County averages 373.4 people per square mile [144.2 people/km²].

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

Census-to-Census Observations ...

Introduction ...

When the Census Bureau takes a census count (or enumeration) for Mount Airy, 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 Mount Airy. 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 Mount Airy 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 Mount Airy, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Mount Airy.

• Continue Reading ...
  • For the 2010 Census, the location was given as:
  • Lat:   39.374420°   (or 39°22'27" N)
  • Lon:   -77.153455°   (or -77°9'12" W)
  • For the 2000 Census, the location given was:
  • Lat:   39.374798°   (or 39°22'29" N)
  • Lon:   -77.155678°   (or -77°9'20" W)
  • The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 641 feet to the east<5> of the location that was used in the 2000 Census.
  • The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#2391316) to Mount Airy. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Mount Airy. The GNIS point has been mapped to the latitude/longitude:
  • Lat:   39.374171°   (or 39°22'27" N)
  • Lon:   -77.154240°   (or -77°9'15" W)
  • The GPS location given for the 2010 Census lies 239.1 feet to the northeast<6> of the point given by the GNIS for Mount Airy. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Mount Airy.

Miscellaneous Information for Mount Airy ...

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 Carroll County or the town of Mount Airy:

• The GNIS Codes ...
  • The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to Mount Airy:
  • GNIS ID for Mount Airy: 2391316
  • GNIS ID for Carroll County: 1696228
  • GNIS ID for State of Maryland: 1714934

• The FIPS Codes ...
  • An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
  • State Code: 24 (Maryland)
  • County Code: 013 (Carroll County)
  • Place Code: 53875 (Mount Airy)
  • State & County Code: 24/013 (Maryland / Carroll County)
  • State & Place Code: 24/53875 (Maryland / Mount Airy)

• Misc. Census Codes ...
  • Mount Airy is located in Census Region #3 (the South Region) and Division #5 (the South Atlantic Division).

• The US Postal Service ZIP Code ...
  • While some people have used a ZIP code to identify a community, the purpose of the ZIP code was to make mail delivery more efficient by grouping addresses together. Although the ZIP Code doesn't specifically identify a town like Mount Airy, it does identify addresses that are in (or near) Mount Airy. It's important to remember that the boundaries of a ZIP Code can be changed, re-assigned or overlapped with other ZIP Codes.
  • The ZIP code for Mount Airy:21771<7>

• 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 Mount Airy.

Off-the-Road Links ...

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

The official website for Carroll County: www.ccgov.carr.org/

The official website for State of Maryland: www.maryland.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)