Introduction

The US Census Bureau defines an urban area by using housing unit density to identify densely developed territory, with the criteria for 2020 including a minimum of 5,000 people or 2,000 housing units, along with a core of census blocks meeting high-density requirements. The definition encompasses residential, commercial, and other non-residential land uses within the urban core and includes adjacent lower-density areas to connect outlying high-density territories. Please see the section on census blocks for maps and tables of individual urban areas in Alabama.

Key Criteria for Urban Areas (2020 Census)

• Population or Housing Unit Threshold: An area must meet one of the following criteria to be considered urban:
  • A minimum population of 5,000 people.
  • A minimum of 2,000 housing units.
• Densely Settled Core: The area must include a dense core of census blocks with a high housing unit density of at least 425 units per square mile.
• Connected Territory: Adjacent areas with lower densities of 200 housing units per square mile are also included to link the core to other built-up areas, creating more meaningful boundaries.
• Delineation Process: The process starts by aggregating census blocks that meet density thresholds, then builds out the urban area, and uses commuting patterns to help split large agglomerations and draw boundaries.

Key Changes and Components

• Shift to Housing Unit Density: The 2020 definition shifted from a population-only density metric to a combination of population and housing unit density, providing more stability and a better measure of the developed urban landscape.
• Elimination of Urbanized Areas and Urban Clusters: The previous distinction between "urbanized areas" (50,000+ people) and "urban clusters" (2,500 to 50,000 people) was eliminated, with all qualifying areas now simply designated as "urban areas".
• Rural is What's Left: Any territory, population, or housing not included within an urban area is considered rural by definition.

The map and table below give geographic data on the 51 urban areas in that lie completely or partially in Alabama. The land and water areas are given in square miles.

Map

In the map below, the urban areas are colored blue; the rest of the state can be considered rural. The census-designated central points can be added as a point layer using the layer control.

Tables

Urban Areas