Decatur County Demographics

A map of Decatur County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	6,997	7,010	90.2%	91.7%
Hispanic	274	211	3.5%	2.8%
Multiracial	267	224	3.4%	2.9%
Black	100	97	1.3%	1.3%
Native American/Other	65	64	0.8%	0.8%
Asian	56	39	0.7%	0.5%

Decatur County, Iowa has an estimated population of 7,759, a slight increase from the 7,645 recorded in the 2020 Census. The population is 90.2% White, 3.5% Hispanic, 3.4% Multiracial, 1.3% Black, 0.8% Native American/Other, and 0.7% Asian. This demographic dot map shows the population of Decatur County, with one dot drawn for each person counted by the Census, color-coded by race.

Decatur has become more racially diverse since the 2020 Census. It is considerably less diverse than Iowa overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Decatur County, that probability was 15.7% in 2020 and 18.4% in the most recent ACS estimates.

Decatur County is ranked the 86th most populous county in Iowa, out of 99 counties. Decatur County was ranked the 86th most populous county in the 2020 Census.

Decatur County's White Population

6,997 residents of Decatur County, or 90.2% of the population, identify as White. The share of White residents in Decatur County is higher than in Iowa overall, where 82.3% of the population is White. Decatur County ranks 52nd statewide in terms of White residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's White population has remained roughly the same. White residents' share of Decatur County's population has decreased from 91.7% to 90.2%.

Decatur County is more White than neighboring Clarke County (77.5% White). Decatur County is less White than neighboring Mercer County (91.1% White), Harrison County (93.8% White), Ringgold County (94.7% White), and Wayne County (93.7% White).

Decatur County's Black Population

100 residents of Decatur County, or 1.3% of the population, identify as Black. The share of Black residents in Decatur County is slightly lower than in Iowa overall, where 3.8% of the population is Black. Decatur County ranks 32nd statewide in terms of Black residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's Black population has grown by an estimated 3.1%. Black residents' share of Decatur County's population has remained roughly unchanged at 1.3%.

Decatur County is more Black than neighboring Clarke County (0.1% Black), Mercer County (0.2% Black), Harrison County (0.8% Black), Ringgold County (0.4% Black), and Wayne County (0.2% Black).

Decatur County's Asian Population

56 residents of Decatur County, or 0.7% of the population, identify as Asian. The share of Asian residents in Decatur County is comparable to the share in Iowa overall, where 2.5% of the population is Asian. Decatur County ranks 42nd statewide in terms of Asian residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's Asian population has grown by an estimated 43.6%. Asian residents' share of Decatur County's population has remained roughly unchanged at 0.7%.

Decatur County is more Asian than neighboring Clarke County (0.6% Asian), Ringgold County (0% Asian), and Wayne County (0.1% Asian). Decatur County is less Asian than neighboring Mercer County (0.9% Asian), and Harrison County (1.2% Asian).

Decatur County's Hispanic Population

274 residents of Decatur County, or 3.5% of the population, identify as Hispanic. The share of Hispanic residents in Decatur County is slightly lower than in Iowa overall, where 7.3% of the population is Hispanic. Decatur County ranks 65th statewide in terms of Hispanic residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's Hispanic population has grown by an estimated 29.9%. Hispanic residents' share of Decatur County's population has increased from 2.8% to 3.5%.

Decatur County is more Hispanic than neighboring Harrison County (0.8% Hispanic), Ringgold County (2.2% Hispanic), and Wayne County (1.2% Hispanic). Decatur County is less Hispanic than neighboring Clarke County (16.8% Hispanic), and Mercer County (4.8% Hispanic).

Decatur County's Native American/Other Population

65 residents of Decatur County, or 0.8% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Decatur County is comparable to the share in Iowa overall, where 0.6% of the population is Native American/Other. Decatur County ranks 13th statewide in terms of Native American/Other residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's Native American/Other population has grown by an estimated 1.6%. Native American/Other residents' share of Decatur County's population has remained roughly unchanged at 0.8%.

Decatur County is more Native American/Other than neighboring Clarke County (0.2% Native American/Other), Mercer County (0.4% Native American/Other), Harrison County (0.3% Native American/Other), Ringgold County (0.3% Native American/Other), and Wayne County (0% Native American/Other).

Decatur County's Multiracial Population

267 residents of Decatur County, or 3.4% of the population, identify as Multiracial. The share of Multiracial residents in Decatur County is comparable to the share in Iowa overall, where 3.5% of the population is Multiracial. Decatur County ranks 30th statewide in terms of Multiracial residents as a share of the population, out of 99 counties.

Since the 2020 Census, Decatur County's Multiracial population has grown by an estimated 19.2%. Multiracial residents' share of Decatur County's population has increased from 2.9% to 3.4%.

Decatur County is more Multiracial than neighboring Mercer County (2.6% Multiracial), Harrison County (3% Multiracial), and Ringgold County (2.5% Multiracial). Decatur County is less Multiracial than neighboring Clarke County (4.9% Multiracial), and Wayne County (4.8% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.