Adair County area

Population and density of Adair County

The Census Bureau estimates that 25,684 people lived in Adair County on July 1, 2025. That ranks #1,647 of 3,222 county equivalents nationally and #43 of 115 in Missouri. Since the April 1, 2020 estimates base of 25,314, the population has grown by 370 (+1.5%), compared with +1.9% for Missouri as a whole.

With 567.3 square miles of land, that is 45 people per square mile (17 per km²), placing Adair County #1,648 nationally for density and #41 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 14 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Adair County

6 incorporated places lie at least partly in Adair County. Together they are home to 18,723 people (72.9%); the other 6,961 (27.1%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Kirksville city, with 17,863 residents in the county.

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Adair County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Adair County is a central county of the Kirksville, MO Micropolitan Statistical Area. Its 2 county equivalents have 29,824 residents on 874.6 square miles of land; Adair County accounts for 64.9% of the land and 86.1% of the residents. By combined land it ranks #232 of 542 micropolitan areas, and #441 by population.

ZIP codes

9 ZIP Code Tabulation Areas have land in Adair County; 5 of them have most of their land inside the county, and the others mainly cover neighboring areas.

635016353363540635446354663547635496355763559

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Adair County

Adair County shares a land border with 7 county equivalents. It has more land than 4 of them. The largest neighbor is Macon County (801.2 mi²) and the smallest is Schuyler County (307.3 mi²). Together with its neighbors, Adair County forms a block of 4,397.2 mi² of land, of which it holds 12.9%.

How big is Adair County compared with U.S. states?

Adair County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Missouri’s county land could hold about 121 areas the size of Adair County.

Another way to picture it: the same land area would fill a square about 23.8 miles (38.3 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Adair County?

Adair County has more land than 1,418 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Adair County at #1,935 nationally by total area, 131 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 0.4%, compared with a national county-equivalent median of 1.2% — 0.8 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Adair County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.