2020 census As of the
2020 census, Cold Spring Harbor had a population of 3,064. This represented a decrease from 4,975 in 2000. There were 975 households in Cold Spring Harbor, of which 39.2% had children under the age of 18 living in them. Of all households, 71.8% were married-couple households, 8.8% were households with a male householder and no spouse or partner present, and 15.9% were households with a female householder and no spouse or partner present. About 12.4% of all households were made up of individuals and 7.6% had someone living alone who was 65 years of age or older. There were 1,020 housing units, of which 4.4% were vacant. The homeowner vacancy rate was 1.4% and the rental vacancy rate was 6.6%.
2000 census There were 1,753 households, out of which 38.8% had children under the age of 18 living with them, 71.8% were
married couples living together, 7.1% had a female householder with no husband present, and 19.2% were non-families. 14.9% of all households were made up of individuals, and 5.8% had someone living alone who was 65 years of age or older. The average household size was 2.84 and the average family size was 3.15. In the CDP, the population was spread out, with 26.7% under the age of 18, 4.2% from 18 to 24, 28.9% from 25 to 44, 26.9% from 45 to 64, and 13.4% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 94.9 males. For every 100 females age 18 and over, there were 92.1 males. The median income for a household in the CDP was $101,122, and the median income for a family was $112,441. Males had a median income of $78,984 versus $44,464 for females. The
per capita income for the CDP was $52,403. About 1.3% of families and 2.2% of the population were below the
poverty line, including 0.4% of those under age 18 and 3.6% of those age 65 or over. ==Arts and culture==