Grundy County Demographics

A map of Grundy County's Population by Race

Grundy County, Iowa has an estimated population of 12,384, a less than 1% change from the 12,329 recorded in the 2020 Census. The population is 94.9% White, 1.8% Hispanic, 1.2% Native American/Other, 1.1% Multiracial, 0.6% Black, and 0.5% Asian. This demographic dot map shows the population of Grundy County, with one dot drawn for each person counted by the Census, color-coded by race.

Grundy 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 Grundy County, that probability was 8.5% in 2020 and 9.9% in the most recent ACS estimates.

Grundy County is ranked the 60th most populous county in Iowa, out of 99 counties. Grundy County was ranked the 60th most populous county in the 2020 Census.

Grundy County's White Population

11,749 residents of Grundy County, or 94.9% of the population, identify as White. The share of White residents in Grundy County is considerably higher than in Iowa overall, where 82.3% of the population is White. Grundy County ranks 5th statewide in terms of White residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's White population has remained roughly the same. White residents' share of Grundy County's population has decreased from 95.6% to 94.9%.

Grundy County is more White than neighboring Butler County (94.6% White), Tama County (78.4% White), Marshall County (66% White), Hardin County (90.1% White), and Black Hawk County (78.1% White).

Grundy County's Black Population

71 residents of Grundy County, or 0.6% of the population, identify as Black. The share of Black residents in Grundy County is slightly lower than in Iowa overall, where 3.8% of the population is Black. Grundy County ranks 78th statewide in terms of Black residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's Black population has grown by an estimated 65.1%. Black residents' share of Grundy County's population has remained roughly unchanged at 0.6%.

Grundy County is more Black than neighboring Butler County (0.2% Black). Grundy County is less Black than neighboring Tama County (0.9% Black), Marshall County (1.6% Black), Hardin County (1.1% Black), and Black Hawk County (9.1% Black).

Grundy County's Asian Population

59 residents of Grundy County, or 0.5% of the population, identify as Asian. The share of Asian residents in Grundy County is comparable to the share in Iowa overall, where 2.5% of the population is Asian. Grundy County ranks 94th statewide in terms of Asian residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's Asian population has grown by an estimated 145.8%. Asian residents' share of Grundy County's population has remained roughly unchanged at 0.5%.

Grundy County is less Asian than neighboring Butler County (1.3% Asian), Tama County (0.7% Asian), Marshall County (4.1% Asian), Hardin County (0.8% Asian), and Black Hawk County (2.7% Asian).

Grundy County's Hispanic Population

219 residents of Grundy County, or 1.8% of the population, identify as Hispanic. The share of Hispanic residents in Grundy County is lower than in Iowa overall, where 7.3% of the population is Hispanic. Grundy County ranks 97th statewide in terms of Hispanic residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's Hispanic population has grown by an estimated 51.0%. Hispanic residents' share of Grundy County's population has increased from 1.2% to 1.8%.

Grundy County is more Hispanic than neighboring Butler County (1.7% Hispanic). Grundy County is less Hispanic than neighboring Tama County (11.7% Hispanic), Marshall County (24.6% Hispanic), Hardin County (5.5% Hispanic), and Black Hawk County (5.2% Hispanic).

Grundy County's Native American/Other Population

153 residents of Grundy County, or 1.2% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Grundy County is comparable to the share in Iowa overall, where 0.6% of the population is Native American/Other. Grundy County ranks 92nd statewide in terms of Native American/Other residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's Native American/Other population has grown by an estimated 512.0%. Native American/Other residents' share of Grundy County's population has increased from 0.2% to 1.2%.

Grundy County is more Native American/Other than neighboring Butler County (0.7% Native American/Other), Marshall County (0.6% Native American/Other), Hardin County (0.4% Native American/Other), and Black Hawk County (1% Native American/Other). Grundy County is less Native American/Other than neighboring Tama County (5.4% Native American/Other).

Grundy County's Multiracial Population

133 residents of Grundy County, or 1.1% of the population, identify as Multiracial. The share of Multiracial residents in Grundy County is slightly lower than in Iowa overall, where 3.5% of the population is Multiracial. Grundy County ranks 54th statewide in terms of Multiracial residents as a share of the population, out of 99 counties.

Since the 2020 Census, Grundy County's Multiracial population has declined by an estimated 55.8%. Multiracial residents' share of Grundy County's population has decreased from 2.4% to 1.1%.

Grundy County is less Multiracial than neighboring Butler County (1.6% Multiracial), Tama County (2.9% Multiracial), Marshall County (3.2% Multiracial), Hardin County (2.1% Multiracial), and Black Hawk County (3.9% 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.