County Maps US

Day County, South Dakota

A county in South Dakota, ranked 32 of 66 by population.

CountyFIPS 46037

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

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Population
5,484
+42 (+0.8%) since 2020
Land area
1,028
square miles. A further 5.7% of the total area is water
Population density
5.3
people per square mile, computed rather than published
County seat
Webster
Seat of county government.
Established
1880
145 years ago
Largest city
Webster city
Population 1,681.

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 Day 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 Day County, South Dakota 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 674 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 Day County ranks

Position among the 66 counties of South Dakota, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn South DakotaNationally
Population5,48432nd of 662,779th of 3,144
Land area1,028 sq mi28th of 66644th of 3,144
Population density5.3 per sq mi34th of 662,756th of 3,144
Median household income$66,03347th of 661,535th of 3,143

Full data for Day County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population5,484Vintage 2025 Population Estimates
Population in 20205,442Vintage 2025 Population Estimates
2020 estimates base?5,452Vintage 2025 Population Estimates
Land area1,028 sq mi2025 Gazetteer Files
Water area62.6 sq mi2025 Gazetteer Files
Total area1,091 sq mi2025 Gazetteer Files
Population density?5.3 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$66,033American Community Survey 2020-2024 5-Year Estimates
Median home value$173,600American Community Survey 2020-2024 5-Year Estimates
Median age44.8American Community Survey 2020-2024 5-Year Estimates
Households2,371American Community Survey 2020-2024 5-Year Estimates
Housing units3,440American 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
-16
53 births, 69 deaths
Net migration
+53
More people moved in than moved out.

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

The 7 areas bordering Day 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
Marshall CountySouth Dakota38 mi4,426
Brown CountySouth Dakota24 mi37,561
Clark CountySouth Dakota24 mi4,031
Roberts CountySouth Dakota18 mi10,255
Codington CountySouth Dakota13 mi29,562
Grant CountySouth Dakota10 mi7,534
Spink CountySouth Dakota6.0 mi6,155

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

All 66 counties of South Dakota

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

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