County Maps US

Clay County, Iowa

A county in Iowa, ranked 47 of 99 by population.

CountyFIPS 19041

Within Iowa
Clay County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Spencer, the county seat, located via the 2025 Census Gazetteer.

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Population
16,202
-139 (-0.9%) since 2020
Land area
567.2
square miles. A further 0.9% of the total area is water
Population density
28.6
people per square mile, computed rather than published
County seat
Spencer
Seat of county government.
Established
1851
174 years ago
Largest city
Spencer city
Population 11,218.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Clay County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Clay County, Iowa from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 800 by 797 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Clay County ranks

Position among the 99 counties of Iowa, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IowaNationally
Population16,20247th of 992,026th of 3,144
Land area567.2 sq mi56th of 991,805th of 3,144
Population density28.6 per sq mi44th of 991,966th of 3,144
Median household income$65,42876th of 991,599th of 3,143

Full data for Clay County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population16,202Vintage 2025 Population Estimates
Population in 202016,341Vintage 2025 Population Estimates
2020 estimates base?16,385Vintage 2025 Population Estimates
Land area567.2 sq mi2025 Gazetteer Files
Water area5.4 sq mi2025 Gazetteer Files
Total area572.6 sq mi2025 Gazetteer Files
Population density?28.6 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$65,428American Community Survey 2020-2024 5-Year Estimates
Median home value$178,600American Community Survey 2020-2024 5-Year Estimates
Median age42.3American Community Survey 2020-2024 5-Year Estimates
Households7,282American Community Survey 2020-2024 5-Year Estimates
Housing units8,157American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-61
153 births, 214 deaths
Net migration
-252
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 8 areas bordering Clay County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Buena Vista CountyIowa24 mi20,449
Dickinson CountyIowa24 mi18,077
Palo Alto CountyIowa24 mi8,899
O'Brien CountyIowa24 mi14,220
Cherokee CountyIowaa single point11,369
Emmet CountyIowaa single point9,107
Osceola CountyIowaa single point5,980
Pocahontas CountyIowaa single point6,819

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 99 counties of Iowa

Open the interactive Iowa county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.