Census Data for Red Oak
Population ...
The most recent Census Estimate<1> was for 2019 and it gave Red Oak a population of 5,270 people.
The last Decennial Census<2> was in 2010, which gave Red Oak a population of 5,742 people.
The city of Red Oak is located in Montgomery County. The 2010 Census gave Montgomery County; a population of 10,740 people. This means that Red Oak had 53.5% of the county's total population, making it Montgomery's most populous community.
At the same time, Iowa had a population of 3,046,355 people, meaning that Red Oak had 0.19% of the total population of Iowa - making it the state's 65th most populous community.
Area ...
The 2010 Census shows that the sampling area for Red Oak has a total area of 4 square miles [10.4 km²]. Of this total, 3.95 square miles [10.2 km²] is land, with the balance (1.4%) being water (0.06 square miles [0.1 km²]).
Montgomery County has a land area of 424.1 square miles [1,098.4 km²]. At 3.95 square miles [10.2 km²], Red Oak has 0.93% of the county's total land area.
- Continue Reading ...
- When the Census Bureau conducts a census for a city like Red Oak, 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 Red Oak reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Red Oak 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: 41° 0' 50" (or 41.01°)
- Lon: -95° 13' 27" (or -95.22°)
- 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, Red Oak had 2,887 Housing Units<3> and with its population of 5,742 people, this averages 1.99 people per Housing Unit.
- Continue Reading ...
- The 2010 Census shows Red Oak had a land area of 3.95 square miles [10.2 km²]. This translates to 721 Housing Units per square mile [278.5 housing units/km²].
- From the Census of 2000: Red Oak had 2,985 Housing Units, a population of 6,197 people and a land area of 3.68 square miles [9.5 km²]. This gives a density of 2.08 people per Housing Unit and 799 Housing Units per square mile [308.6 housing units/km²].
- Note: Repeating the caution above (under Population Density), be aware that when comparing Housing Units between the 2010 Census and the 2000 Census, there were changes in the sampling area for Red Oak and you need to be careful when comparing between the censuses. More information about the changes can be found in the section called Census-to-Census Observations ... (see below).
Montgomery County ...
The community of Red Oak is located in Montgomery County<4> and is the County Seat for Montgomery County.
The county had a population of 10,740 people at the 2010 Census. With it's population of 5,742 people, Red Oak represented 53.5% of the county's total.
In addition, where the city of Red Oak has a population density of 1,434 people per square mile [553 people/km²], Montgomery County averages 25.32 people per square mile [9.78 people/km²].
For more information, please visit our Census Page for Montgomery County.
Census-to-Census Observations ...
Introduction ...
When the Census Bureau takes a census count (or enumeration) for Red Oak, 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 Red Oak. 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 Red Oak 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 Red Oak, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Red Oak.
- Continue Reading ...
- For the 2010 Census, the location was given as:
- Lat: 41.014130° (or 41°0'50" N)
- Lon: -95.224371° (or -95°13'27" W)
- For the 2000 Census, the location given was:
- Lat: 41.011681° (or 41°0'42" N)
- Lon: -95.227227° (or -95°13'38" W)
- The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 1,189 feet to the northeast<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 (#2396337) to Red Oak. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Red Oak. The GNIS point has been mapped to the latitude/longitude:
- Lat: 41.014137° (or 41°0'50" N)
- Lon: -95.224840° (or -95°13'29" W)
- The GPS location given for the 2010 Census lies 129 feet to the east<6> of the point given by the GNIS for Red Oak. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Red Oak.
Miscellaneous Information for Red Oak ...
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 Montgomery County or the city of Red Oak:
- The GNIS Codes ...
- The FIPS Codes ...
- An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
- State Code: 19 (Iowa)
- County Code: 137 (Montgomery County)
- Place Code: 66135 (Red Oak)
- State & County Code: 19/137 (Iowa / Montgomery County)
- State & Place Code: 19/66135 (Iowa / Red Oak)
- Misc. Census Codes ...
- Red Oak is located in Census Region #2 (the Midwest Region) and Division #4 (the West North-Central 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 Red Oak, 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 Red Oak:<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 Red Oak.
Off-the-Road Links ...
The official website for Red Oak: https://city.redoakiowa.com/
The official website for State of Iowa: https://www.iowa.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)
Footnotes ...
| <1> | Every year, the US Census Bureau creates a population estimate for the preceeding year. Keep in mind that this value is an estimate and not an actual count. The most recent Census estimate is for the year 2019. |
| <2> | Every 10 years (eg- 1990, 2000, 2010), the US Census Bureau conducts a Constitutionally-mandated count (or enumeration) of people living within the United States. This count is called a Decennial Census. The last Decennial Census was the 2010 Census, with the next one planned for 2020. |
| <3> | A Housing Unit is a broad term for those places where people live (whether occupied or temporarily vacant), such as a house, an apartment, a mobile home, or an area that is considered as a separate living quarter. Separate living quarters (consisting of one or more rooms) are considered to be those places where people live, sleep and eat separately from others and that have access to the outside (either directly or by a shared hallway). |
| <4> | If you're interested in how the shape of Iowa's counties, including Montgomery, have changed over time, we recommend the Atlas of Historical County Boundaries. |
| <5> | The calculated bearing (or angle) to the 2010 Census location is 318 degrees and a distance of 1,189 feet. |
| <6> | The calculated bearing (or angle) to the GNIS point is 268 degrees and a distance of 129 feet. |
| <7> | When looking for a ZIP Code, whether Red Oak or elsewhere, it's always best to check the website of the United States Postal Service (USPS). |