In the Nebraska license plate system, Cedar County is represented by the prefix 13 (it had the thirteenth-largest number of vehicles registered in the county when the license plate system was established in 1922).
1860 - 246 1870 - 1,032 1880 - 2,899 1890 - 7,028 1900 - 12,467 1910 - 15,191 1920 - 16,225 1930 - 16,427 1940 - 15,126 1950 - 13,843 1960 - 13,368 1970 - 12,192 1980 - 11,375 1990 - 10,131 2000 - 9,615
As of the census of 2000, there were 9,615 people, 3,623 households, and 2,565 families residing in the county. The population density was 13 people per square mile (5/km²). There were 4,200 housing units at an average density of 6 per square mile (2/km²). The racial makeup of the county was 99.07% White, 0.10% Black or African American, 0.20% Native American, 0.04% Asian, 0.01% Pacific Islander, 0.18% from other races, and 0.40% from two or more races. 0.43% of the population were Hispanic or Latino of any race. 69.8% were of German and 5.1% American ancestry according to Census 2000.
There were 3,623 households out of which 34.80% had children under the age of 18 living with them, 63.60% were married couples living together, 4.30% had a female householder with no husband present, and 29.20% were non-families. 27.00% of all households were made up of individuals and 15.70% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.20.
In the county the population was spread out with 29.40% under the age of 18, 6.00% from 18 to 24, 24.20% from 25 to 44, 20.30% from 45 to 64, and 20.00% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 100.10 males. For every 100 females age 18 and over, there were 97.10 males.
The median income for a household in the county was $33,435, and the median income for a family was $39,422. Males had a median income of $26,707 versus $18,370 for females. The per capita income for the county was $15,514. About 6.30% of families and 9.10% of the population were below the poverty line, including 10.70% of those under age 18 and 9.70% of those age 65 or over.