Yuma County area

Population and density of Yuma County

The Census Bureau estimates that 224,449 people lived in Yuma County on July 1, 2025. That ranks #321 of 3,222 county equivalents nationally and #6 of 15 in Arizona. Since the April 1, 2020 estimates base of 205,006, the population has grown by 19,443 (+9.5%), compared with +6.5% for Arizona as a whole.

With 5,513.8 square miles of land, that is 41 people per square mile (16 per km²), placing Yuma County #1,739 nationally for density and #4 in Arizona. The median county equivalent has 47 people per square mile; the Arizona median is 17. Put another way, there are about 16 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 Yuma County

4 incorporated places lie at least partly in Yuma County. Together they are home to 164,862 people (73.5%); the other 59,587 (26.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Yuma city, with 105,227 residents in the county. Among places with at least 1,000 residents in 2020, San Luis city grew fastest since then (+18.5%).

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

Metropolitan area

Yuma County is a central county of the Yuma, AZ Metropolitan Statistical Area. Yuma County is the area’s only county equivalent, so the metro area has the same 5,513.8 square miles of land. By combined land it ranks #42 of 393 metropolitan areas, and #218 by population.

ZIP codes

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

85333853368534785349853508535285356853648536585367

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 Yuma County

Yuma County shares a land border with 4 county equivalents, including 1 in California. It has more land than 2 of them. The largest neighbor is Maricopa County (9,202 mi²) and the smallest is Imperial County (4,175.5 mi²). Together with its neighbors, Yuma County forms a block of 32,576.6 mi² of land, of which it holds 16.9%.

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

Yuma County has more land than 3 of the 50 states. It is about 1.1 times the land area of Connecticut (4,842.5 mi²), while Hawaii, the next larger state, has 1.2 times as much land (6,422.6 mi²). Arizona’s county land could hold about 21 areas the size of Yuma County.

Another way to picture it: the same land area would fill a square about 74.3 miles (119.5 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 Yuma County?

Yuma County has more land than 3,154 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 Yuma County at #72 nationally by total area, 4 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 0.1%, compared with a national county-equivalent median of 1.2% — 1.1 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 Yuma 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.