The ZIP code 08820, comprising South Plainfield in New Jersey, has exhibited a consistently high population density over the past decade, with the most recent data from 2022 showing a density of 3,773.57 people per square mile. This places the area firmly in the Urban classification, which is characterized by population densities between 3,000 and 10,000 people per square mile.

The Urban lifestyle in South Plainfield is likely to feature a mix of multi-story residential buildings and commercial establishments, supported by well-developed infrastructure and a wide range of services. Residents in this area typically live in smaller spaces, ranging from 500 to 1,000 square feet, which is consistent with the estimated 14,935 housing units corresponding to the 2022 population, given the national average household size of 2.61.

The population of South Plainfield has remained relatively stable over the past decade, with minor fluctuations. The population peaked in 2015 at 40,465 and has since slightly decreased to 38,981 in 2022. This suggests that the area has reached a mature stage of urban development, with a well-established community and a balanced mix of residential and commercial activities.