Major highways

• U.S. Highway 34
• Iowa Highway 5
• Iowa Highway 137

Adjacent counties

• Marion County (northwest)
• Mahaska County (northeast)
• Wapello County (east)
• Appanoose County (south)
• Lucas County (west)

2020 census

The 2020 census recorded a population of 7,577 in the county, with a population density of 17.5217/sq mi (6.7652/km²). 96.86% of the population reported being of one race. 93.81% were non-Hispanic White, 0.25% were Black, 1.54% were Hispanic, 0.17% were Native American, 0.21% were Asian, 0.03% were Native Hawaiian or Pacific Islander and 3.99% were some other race or more than one race. There were 3,636 housing units, of which 3,116 were occupied.^[1]

2010 census

The 2010 census recorded a population of 7,970 in the county, with a population density of 18.389/sq mi (7.100/km²). There were 3,884 housing units, of which 3,213 were occupied.^[12]

2000 census

As of the census^[13] of 2000, there were 8,016 people, 3,228 households, and 2,211 families in the county. The population density was 18 people per square mile (6.9 people/km²). There were 3,588 housing units at an average density of 8 units per square mile (3.1 units/km²). The racial makeup of the county was 98.40% White, 0.20% Black or African American, 0.36% Native American, 0.40% Asian, 0.12% from other races, and 0.51% from two or more races. 0.50% of the population were Hispanic or Latino of any race.

Of the 3,228 households, 30.50% had children under the age of 18 living with them, 56.20% were married couples living together, 8.60% had a female householder with no husband present, and 31.50% were non-families. 28.00% of households were one person, and 15.30% were one person aged 65 or older. The average household size was 2.43 and the average family size was 2.97.

In the county, the population was spread out, with 25.30% under the age of 18, 7.20% from 18 to 24, 25.00% from 25 to 44, 23.00% from 45 to 64, and 19.50% 65 or older. The median age was 40 years. For every 100 females there were 94.90 males. For every 100 females age 18 and over, there were 92.60 males.

The median household income was $34,877 and the median family income was $41,611. Males had a median income of $31,667 versus $21,401 for females. The per capita income for the county was $17,155. About 5.60% of families and 9.00% of the population were below the poverty line, including 12.20% of those under age 18 and 5.90% of those age 65 or over.

Cities

Unincorporated communities

Ghost town

• Buxton, the largest town with a majority-black population in the early 20th century

Townships

Population ranking

The population ranking of the following table is based on the 2020 census of Monroe County.^[1]

† county seat