Weld County area

Population and density of Weld County

The Census Bureau estimates that 378,426 people lived in Weld County on July 1, 2025. That ranks #206 of 3,222 county equivalents nationally and #7 of 64 in Colorado. Since the April 1, 2020 estimates base of 328,981, the population has grown by 49,445 (+15%), compared with +4.1% for Colorado as a whole.

With 3,985 square miles of land, that is 95 people per square mile (37 per km²), placing Weld County #1,032 nationally for density and #10 in Colorado. The median county equivalent has 47 people per square mile; the Colorado median is 11. Put another way, there are about 6.7 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 Weld County

32 incorporated places lie at least partly in Weld County. Together they are home to 330,426 people (87.3%); the other 48,000 (12.7%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Greeley city, with 115,073 residents in the county. Among places with at least 1,000 residents in 2020, Keenesburg town grew fastest since then (+68%).

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

Metropolitan area

Weld County is a central county of the Greeley, CO Metropolitan Statistical Area. Weld County is the area’s only county equivalent, so the metro area has the same 3,985 square miles of land. By combined land it ranks #73 of 393 metropolitan areas, and #150 by population. It belongs to the Denver-Aurora-Greeley, CO Combined Statistical Area.

ZIP codes

43 ZIP Code Tabulation Areas have land in Weld County; 35 of them have most of their land inside the county, and the others mainly cover neighboring areas.

80504805138051480516805208052480530805348053780542805438054680549805508060180603806108061180612806158062080621806228062380624806318063480642806438064480645806468064880649806508065180652806548072980732807428075482082

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 Weld County

Weld County shares a land border with 8 county equivalents, including 2 in Wyoming and Nebraska. It has more land than every one of them. The largest neighbor is Laramie County (2,685.9 mi²) and the smallest is Broomfield County (33 mi²). Together with its neighbors, Weld County forms a block of 15,263.8 mi² of land, of which it holds 26.1%.

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

Weld County has more land than 2 of the 50 states. It is about 2 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.2 times as much land (4,842.5 mi²). Colorado’s county land could hold about 26 areas the size of Weld County.

Another way to picture it: the same land area would fill a square about 63.1 miles (101.6 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 Weld County?

Weld County has more land than 3,100 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 Weld County at #130 nationally by total area, 8 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 0.8%, compared with a national county-equivalent median of 1.2% — 0.4 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 Weld 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.