Jefferson County

2020 census

As of the 2020 census, the county had a population of 256,526. The median age was 37.4 years. 23.7% of residents were under the age of 18 and 15.2% of residents were 65 years of age or older. For every 100 females there were 104.3 males, and for every 100 females age 18 and over there were 104.6 males age 18 and over.

The racial makeup of the county was 42.5% White, 33.1% Black or African American, 0.7% American Indian and Alaska Native, 3.9% Asian, <0.1% Native Hawaiian and Pacific Islander, 11.0% from some other race, and 8.8% from two or more races. Hispanic or Latino residents of any race comprised 23.0% of the population.

90.2% of residents lived in urban areas, while 9.8% lived in rural areas.

There were 95,658 households in the county, of which 32.9% had children under the age of 18 living in them. Of all households, 41.5% were married-couple households, 21.0% were households with a male householder and no spouse or partner present, and 31.9% were households with a female householder and no spouse or partner present. About 29.3% of all households were made up of individuals and 11.5% had someone living alone who was 65 years of age or older.

There were 108,330 housing units, of which 11.7% were vacant. Among occupied housing units, 60.7% were owner-occupied and 39.3% were renter-occupied. The homeowner vacancy rate was 1.7% and the rental vacancy rate was 12.2%.

2000 census

As of the 2000 census, there were 252,051 people, 92,880 households, and 63,808 families residing in the county. The population density was 279 people per square mile (108 people/km2). There were 102,080 housing units at an average density of 113 units per square mile (44/km2). The racial makeup of the county was 57.24% White, 33.74% Black or African American, 0.34% Native American, 2.89% Asian, 0.03% Pacific Islander, 4.26% from other races, and 1.50% from two or more races. 10.53% of the population were Hispanic or Latino of any race. 8.3% were of American, 7.2% French, 6.2% German, 5.8% English and 5.3% Irish ancestry according to census 2000.

There were 92,880 households, out of which 33.00% had children under the age of 18 living with them, 48.40% were married couples living together, 16.20% had a female householder with no husband present, and 31.30% were non-families. 27.30% of all households were made up of individuals, and 11.00% had someone living alone who was 65 years of age or older. The average household size was 2.55 and the average family size was 3.12.

In the county, the population was spread out, with 25.90% under the age of 18, 10.00% from 18 to 24, 29.30% from 25 to 44, 21.10% from 45 to 64, and 13.60% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 101.10 males. For every 100 females age 18 and over, there were 100.20 males.