Spencer, South Dakota Demographics & Population 2026

A note before these figures: with a population of 103, Spencer's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.

Population Overview

Spencer is a small community located in South Dakota, within McCook County. The total population is 103. It ranks as the 300th most populous out of 439 Census-designated places in South Dakota.

Age Demographics

The median age in Spencer is 36.8 years. This is 3% lower than the state median of 38.0 years. 13.6% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.

Economy, Income & Housing

The median household income in Spencer is $67,188. This is 11% lower than the state median of $75,081. It is also 17% lower than the national median of $80,734. The poverty rate stands at 2.9%. This is 76% lower than the state poverty rate of 11.9%. This exceptionally low poverty rate indicates strong economic prosperity across the community. The survey records no unemployed residents in Spencer, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $155,600. Housing costs are 40% lower than the state median of $257,400. With a home-value-to-income ratio of just 2.3x, Spencer is one of the most affordable housing markets in the area. 84.2% of occupied housing units are owner-occupied. This homeownership rate is 23% higher than the state average of 68.6%.

Race & Ethnicity

Spencer has a predominantly White (non-Hispanic) population, comprising 96.1% of all residents. Hispanic or Latino residents account for 1.0%. The Hispanic or Latino population (1.0%) is well below the state average of 4.8%.

Education

18.1% of residents aged 25 and older hold a bachelor's degree or higher. This is 43% lower than the state rate of 31.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 94.4%.

Data Sources & Methodology

All demographic data for Spencer, South Dakota is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against South Dakota state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 439 Census-designated places in South Dakota. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.