Harbor Island, SC population, income and ZIP codes

Harbor Island CDP is a very small community in South Carolina, with 310 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #380 of 475 ranked by population — larger than 20% of them. The median age here is 69.5 years against 39.1 nationally, a markedly older profile that usually tracks retirees staying put and younger households leaving for work. At this population the ACS sample is small, so the margin of error around every dollar figure below is wide — treat the numbers as a band, not a point, and expect them to move between annual releases without the place itself changing.

Households in Harbor Island CDP earn a median of $100,250 a year, 27.6% above the national figure of $78,538 and 89% above the $53,071 median for the 263 South Carolina cities we cover. The median is the midpoint household, not an average, so a handful of very high earners cannot drag it upward the way they distort a mean. Poverty reaches 4.2% of residents here, less than half the 12.4% national rate.

The typical owner-occupied home in Harbor Island CDP is valued at $284,500, 6.2% below the national figure and 61% above the $177,100 peer median, while median gross rent runs not published a month. The home-price-to-income ratio works out to 2.8×, against roughly 3.9× nationally, so buying is easier here than in the average US market. 84.2% of occupied homes are owner-occupied versus 65% nationally, an owner-dominated market where rental listings are scarce and rent medians rest on a thin sample. Rent is reported gross — contract rent plus tenant-paid utilities — which is why it runs above the advertised price on a listing for the same unit.

A median age of 69.5 puts Harbor Island CDP well into retirement-weighted territory, which pulls median household income down even where household wealth is high, because retirement draws are counted differently from wages. With 310 residents, a handful of survey responses moves every median on this page. Compare Harbor Island CDP against its county rather than against national figures.

The Census withheld gross rent for Harbor Island CDP because the sample was too thin to publish at this geography. Those values were suppressed at the source, not lost in our dataset, and we do not model a replacement. Everything else on this page comes straight from the ACS 2019-2023 ACS 5-year tables.