According to the United States Census Bureau, Caldwell has a total area of 3.9 square miles (10.2 km2), of which 0.03 square miles (0.07 km2), or 0.66%, is water.[5]
As of the 2020 United States census, there were 3,993 people, 1,694 households, and 896 families residing in the city.
As of the census[2] of 2000, there were 3,449 people, 1,322 households, and 938 families residing in the city. The population density was 1,021.4 inhabitants per square mile (394.4/km2). There were 1,485 housing units at an average density of 439.8 per square mile (169.8/km2). The racial makeup of the city was 71.24% White, 12.64% African American, 0.17% Native American, 0.09% Asian, 13.71% from other races, and 2.15% from two or more races. Hispanic or Latino of any race were 22.96% of the population.
There were 1,322 households, out of which 36.5% had children under the age of 18 living with them, 52.5% were married couples living together, 14.1% had a female householder with no husband present, and 29.0% were non-families. 26.3% of all households were made up of individuals, and 15.8% had someone living alone who was 65 years of age or older. The average household size was 2.61 and the average family size was 3.16.
In the city, the population was spread out, with 28.8% under the age of 18, 9.5% from 18 to 24, 26.7% from 25 to 44, 20.5% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 87.0 males. For every 100 females age 18 and over, there were 83.2 males.
The median income for a household in the city was $29,936, and the median income for a family was $37,658. Males had a median income of $25,745 versus $20,306 for females. The per capita income for the city was $14,141. About 14.2% of families and 17.9% of the population were below the poverty line, including 21.0% of those under age 18 and 12.2% of those age 65 or over.
The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Caldwell has a humid subtropical climate, abbreviated "Cfa" on climate maps.[10]
^Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race.[9]