Clay County GIS Maps
Clay County, Iowa, has 16,384 residents across 18,369 parcels and covers 567.2 square miles. The population declined 1.7% between the 2010 and 2020 census. More residents left than arrived over that decade. The FIPS code for Clay County is 19041.
Spencer is the county's largest population center. Clay County also includes 10 zip codes, 7 public school districts and 33 municipalities. Those boundaries help explain why population, schools, and housing can look different from one part of the county to another. The map below shows how those county lines, zip codes, and school districts fit together, and the sections that follow use that same geography to show parcel data, population, demographics, school enrollment and housing patterns in more detail.
Maps, GIS layers, Parcels and sample data. Paid packages add full layers, analytics and database files.
Clay County Trends
- Population
- 16,384▾
- Median Home Value
- $171,500▴
- K-12 Enrollment
- 4,601▾
County analytics dashboards with historical trends & projections included in package downloads.
Free starter access previews county maps, lightweight GIS, and sample data. Paid packages unlock full GIS layers, analytics, and database files.
Clay County Maps
The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.
County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.
Clay County Parcels
Clay County has 18,369 mapped parcels covering 344,218 acres. Agricultural land accounts for 51.3% of parcels. Residential follows at 34.2% and commercial at 8.5%. The records carry 7,929 distinct owner names. Owner names are on nearly every parcel. Site addresses reach 82.4%. Browse the interactive Clay County Parcel viewer here.
Clay County Parcel Data Coverage
| Field | Parcels | Coverage |
|---|---|---|
| Parcel ID | 18,369 | 100% |
| Owner name | 18,178 | 99.0% |
| Owner mailing address | 0 | 0% |
| Site address | 15,129 | 82.4% |
| Land use code | 0 | 0% |
| Land use description | 18,191 | 99.0% |
| Assessed value | 0 | 0% |
| Land value | 0 | 0% |
| Improvement value | 0 | 0% |
| Acreage | 0 | 0% |
| Parcel boundary | 18,369 | 100% |
| Download all Clay County parcels. | ||
Field coverage measured across all Clay County parcel records.
Clay County Population
Clay County had 16,384 residents in 2020. That was 1.7% lower than in 2010. Clay County had 988 fewer people in 2020 than it did in 2000, which points to a long-term population decline. The county is fairly spread out, with about 29 people per square mile. Some of the county's most populated postal areas include Spencer, Everly and Royal.
Population Trend in Clay County IA
Clay County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.
Clay County Zip Codes
Clay County has 10 zip codes. Some of the county's most populated zip codes include Spencer (51301), Everly (51338) and Royal (51357). Spencer is the largest zip by population, with about 12,606 residents or 77% of the county total. Together, the three largest zips account for about 86% of all county residents based on 2020 population estimates.
Most Populated Zip Codes in Clay County IA
| ZIP | Area | Population | Trend |
|---|---|---|---|
| 51301 | Spencer | 12,606 | ▾ -0.7% |
| 51338 | Everly | 950 | ▾ -5% |
| 51357 | Royal | 611 | ▾ -16.1% |
| 51047 | Peterson | 588 | ▾ -9% |
| 51333 | Dickens | 440 | ▾ -15.7% |
| Download all zip code data | |||
Clay County Zip Code populations and trends per most recent census data.
Clay County Demographics
Clay County has a median age of 41.8, which makes the county a little older than Iowa overall. About 23.1% of residents are under 18, while 21.9% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 27.8% of the population, which points to a solid working-age base. About 26% of adults have a bachelor's degree or higher, above the statewide figure of 30.9%. The county is mostly White by population, though Hispanic, Asian, Black and multiracial residents are also part of the local mix.
Key Demographics for Clay County IA
Median Age
41.8
Under 18
23.1%
Age 65+
21.9%
Bachelor's+
26%
Clay County School Districts
Clay County is served by 7 public school districts with 4,601 students enrolled in 2024. The largest districts on the county map are Spencer Community, Okoboji Community and Sioux Central Community. Those three districts account for about 85% of public school enrollment in the map area. Total enrollment has stayed fairly steady in recent years, based on district totals from 2017 to 2024.
Largest School Districts by Enrollment in Clay County IA
| District | Enrollment | Share | Trend |
|---|---|---|---|
| Spencer Community School District | 2,094 | 45.5% | ▾ -3.1% |
| Okoboji Community School District | 1,196 | 26% | ▾ -1.4% |
| Sioux Central Community School District | 639 | 13.9% | — 0% |
| Graettinger-Terril Community School District | 325 | 7.1% | ▾ -4.1% |
| Laurens-Marathon Community School District | 147 | 3.2% | ▴ 1.4% |
| Download all school district data | |||
Clay County school district enrollment and trends per most recent NCES reporting data.
Clay County Housing & Real Estate
Clay County has a median home value of $171,500 and a median gross rent of $798. About 73% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run below the Iowa median, while rents come in below the state average. In March 2026, the median listing price was $167,000 and homes spent about 101 days on the market.
Clay County Housing Mix
Clay County housing mix: owner, renter and vacant units.
Clay County Housing Trends
Clay County median home value and rent trend (last 5 years).
Businesses in Clay County, IA
Clay County has 970 business listings across 362 categories. The largest categories in Clay County business listings are Churches & Religious Organizations (28, 2.9%), Parks & Recreation (18, 1.9%), and Auto Repair (16, 1.6%). The full Clay County business listings dataset includes names, categories, addresses and contact details where available. Clay County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.
Top Business Categories in Clay County, IA
| Category | Businesses | Share |
|---|---|---|
| Churches & Religious Organizations | 28 | 2.9% |
| Parks & Recreation | 18 | 1.9% |
| Auto Repair | 16 | 1.6% |
| Insurance Agencies | 15 | 1.5% |
| Financial Service | 12 | 1.2% |
| Contractors | 12 | 1.2% |
| Banks & Credit Unions | 11 | 1.1% |
| Farm | 11 | 1.1% |
| Convenience Stores | 11 | 1.1% |
| Chiropractors | 11 | 1.1% |
Clay County Business Listings
| Business | Category | City |
|---|---|---|
| Spencer Inn & Suites | Accommodation | Spencer |
| Winther Stave & Co | Accountant | Spencer |
| Spencer Soccer Complex | Active Life | Spencer |
| F8 Creative | Advertising Agency | Spencer |
| Growmark FS | Agricultural Cooperatives | Royal |
| Superior Crop Products | Agricultural Service | Linn Grove |
| Purple Pursuit | Agriculture | Spencer |
| Spencer Municipal Airport | Airport | Spencer |
| Gary's On The River | American Restaurants | Spencer |
| People For Pets | Animal Shelters | Spencer |
| Download Clay County business listings | ||
Clay County business listings sourced from Overture Maps. Includes locations with a high level of confidence.
Clay County Basemaps
Clay County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.
Get the Full Clay County Data Package
This page shows a preview of what's included in the Clay County data package. The full package gives you a ready-to-use county data system with GIS layers, historical data, maps, database files and planning tools that save hours of manual data gathering, cleanup and joins. Everything is organized to help you skip data wrangling and start analysis faster.
- 20+ GIS layers for parcels, zip codes, school districts, roads, water, boundaries and more
- Historical county demographics, housing, income and trend data
- ZIP code population files and school district enrollment history
- Database files, markdowns, AI-ready prompts and documentation
- Map exports in PNG, JPEG, PDF, SVG and GeoTIFF formats
- Offline-ready data explorer, map and analytics tools
Paid packages support commercial use, client work, and derived outputs. Some package contents may include source-specific attribution or provider notices. See Licensing & Data Source Notices.
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Nearby Counties
Browse county data pages for the counties that border Clay County. These nearby pages include the same mix of county maps, demographic summaries, school district context, housing trends and package links.