Harbor Island CDP, South Carolina Demographics & Population 2026

Population Overview

Harbor Island CDP is a small community located in South Carolina. The total population is 310. It ranks as the 380th most populous out of 475 cities and towns in South Carolina.

Age Demographics

The median age in Harbor Island CDP is 69.5 years. This is 73% higher than the state median of 40.1 years. Only 0.0% of residents are under 18, indicating fewer families with children. 11.0% 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 Harbor Island CDP is $100,250. This is 50% higher than the state median of $66,818. Compared to the national median of $78,538, household income here is 28% higher. The poverty rate stands at 4.2%. This is 70% lower than the state poverty rate of 14.2%. This exceptionally low poverty rate indicates strong economic prosperity across the community. The unemployment rate is 0.0%. This is 100% lower than the state rate of 5.0%. The median home value is $284,500. Housing costs are 20% higher than the state median of $236,700. With a home-value-to-income ratio of just 2.8x, Harbor Island CDP is one of the most affordable housing markets in the area. 84.3% of occupied housing units are owner-occupied. This homeownership rate is 18% higher than the state average of 71.4%.

Race & Ethnicity

Harbor Island CDP has a predominantly White (non-Hispanic) population, comprising 97.1% of all residents. The White (non-Hispanic) population is significantly higher than the state average (97.1% vs 62.2%).

Education

80.8% of residents aged 25 and older hold a bachelor's degree or higher. This places Harbor Island CDP in the top 10% of all cities in the state for educational attainment. This is 157% higher than the state rate of 31.5%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 94.8%. Notably, 38.8% of adults hold a graduate or professional degree, indicating a highly educated workforce.

Data Sources & Methodology

All demographic data for Harbor Island CDP, South Carolina is sourced from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates (2019-2023). The ACS collects data from approximately 3.5 million households annually, providing reliable estimates for communities of all sizes. Comparisons are made against South Carolina state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 475 Census-designated places in South Carolina. For official data, visit data.census.gov.