2020 census
As of the 2020 census, Johnson had a population of 3,609. The median age was 35.4 years. 21.9% of residents were under the age of 18 and 12.1% of residents were 65 years of age or older. For every 100 females, there were 95.9 males, and for every 100 females age 18 and over, there were 93.2 males.[6][7]
87.1% of residents lived in urban areas, while 12.9% lived in rural areas.[8]
As of the 2020 census, there were 1,487 households and 902 families residing in the city. Of the households, 30.5% had children under the age of 18 living in them. Of all households, 47.8% were married-couple households, 17.4% were households with a male householder and no spouse or partner present, and 26.1% were households with a female householder and no spouse or partner present. About 26.9% of all households were made up of individuals, and 8.1% had someone living alone who was 65 years of age or older.[6]
There were 1,595 housing units, of which 6.8% were vacant. The homeowner vacancy rate was 1.8% and the rental vacancy rate was 7.0%.[6]
2000 census
As of the census[9] of 2000, there were 2,319 people, 928 households, and 638 families residing in the city. The population density was 751.2 inhabitants per square mile (290.0/km2). There were 990 housing units at an average density of 320.7 per square mile (123.8/km2). The racial makeup of the city was 91.55% White, 1.42% Black or African American, 0.69% Native American, 2.11% Asian, 0.09% Pacific Islander, 1.68% from other races, and 2.46% from two or more races; 3.19% of the population were Hispanic or Latino of any race.
There were 928 households, out of which 37.6% had children under the age of 18 living with them, 55.5% were married couples living together, 10.1% had a female householder with no husband present, and 31.3% were non-families. 22.7% of all households were made up of individuals, and 4.1% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 2.98.
In the city, the population was spread out, with 27.8% under the age of 18, 10.3% from 18 to 24, 42.8% from 25 to 44, 13.6% from 45 to 64, and 5.5% who were 65 years of age or older. The median age was 29 years. For every 100 females, there were 91.3 males. For every 100 females age 18 and over, there were 87.6 males.
The median income for a household in the city was $44,556, and the median income for a family was $51,618. Males had a median income of $35,189 versus $25,625 for females. The per capita income for the city was $21,502. About 5.4% of families and 7.6% of the population were below the poverty line, including 10.2% of those under age 18 and 9.6% of those age 65 or over.
