Census Data for Oakley
Population ...
The most recent Census Estimate<1> was for 2019 and it gave Oakley a population of 42,338 people.
The last Decennial Census<2> was in 2010, which gave Oakley a population of 35,432 people.
The city of Oakley is located in Contra Costa County. The 2010 Census gave Contra Costa County; a population of 1,049,025 people. This means that Oakley had 3.38% of the county's total population, making it Contra Costa's 10th most populous community.
At the same time, California had a population of 37,253,956 people, meaning that Oakley had 0.1% of the total population of California - making it the state's 213rd most populous community.
Area ...
The 2010 Census shows that the sampling area for Oakley has a total area of 16.16 square miles [41.8 km²]. Of this total, 15.85 square miles [41.1 km²] is land, with the balance (1.87%) being water (0.3 square miles [0.8 km²]).
Contra Costa County has a land area of 715 square miles [1,854.3 km²]. At 15.85 square miles [41.1 km²], Oakley has 2.21% of the county's total land area.
- Continue Reading ...
- When the Census Bureau conducts a census for a city like Oakley, 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 Oakley reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Oakley 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: 37° 59' 38" (or 37.99°)
- Lon: -121° 41' 28" (or -121.69°)
Housing Units ...
At the time of the 2010 Census, Oakley had 11,484 Housing Units<3> and with its population of 35,432 people, this averages 3.09 people per Housing Unit.
- Continue Reading ...
- The 2010 Census shows Oakley had a land area of 15.85 square miles [41.1 km²]. This translates to 710 Housing Units per square mile [274.5 housing units/km²].
Contra Costa County ...
The community of Oakley is located in Contra Costa County<4>.
The county had a population of 1,049,025 people at the 2010 Census. With it's population of 35,432 people, Oakley represented 3.38% of the county's total.
In addition, where the city of Oakley has a population density of 2,193 people per square mile [846 people/km²], Contra Costa County averages 1,465 people per square mile [565 people/km²].
For more information, please visit our Census Page for Contra Costa County.
Census-to-Census Observations ...
Introduction ...
When the Census Bureau takes a census count (or enumeration) for Oakley, 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 Oakley. 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 Oakley 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 Oakley, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Oakley.
- Continue Reading ...
- For the 2010 Censuses, the location was given as:
Lat: 37.993936° (or 37°59'38" N)
- The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#2411294) to Oakley. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Oakley. The GNIS point has been mapped to the latitude/longitude:
- Lat: 37.992811° (or 37°59'34" N)
- Lon: -121.695230° (or -121°41'42" W)
- The GPS location given for the 2010 Census lies 1,244 feet to the east<5> of the point given by the GNIS for Oakley. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Oakley.
Lon: -121.691139° (or -121°41'28" W)
Miscellaneous Information for Oakley ...
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 Contra Costa County or the city of Oakley:
- The GNIS Codes ...
- The FIPS Codes ...
- An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
- State Code: 06 (California)
- County Code: 013 (Contra Costa County)
- Place Code: 53070 (Oakley)
- State & County Code: 06/013 (California / Contra Costa County)
- State & Place Code: 06/53070 (California / Oakley)
- Misc. Census Codes ...
- Oakley is located in Census Region #4 (the West Region) and Division #9 (the Pacific 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 city like Oakley, it does identify addresses that are in (or near) Oakley. 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 Oakley:94561<6>
- 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 Oakley.
Off-the-Road Links ...
The official website for Oakley: www.ci.oakley.ca.us/
The official website for Contra Costa County: www.co.contra-costa.ca.us/
The official website for State of California: https://www.ca.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 California's counties, including Contra Costa, have changed over time, we recommend the Atlas of Historical County Boundaries. |
| <5> | The calculated bearing (or angle) to the GNIS point is 289 degrees and a distance of 1,244 feet. |
| <6> | When looking for a ZIP Code, whether Oakley or elsewhere, it's always best to check the website of the United States Postal Service (USPS). |