| | North Sea, NY | Westhampton, NY | United States |
| Population | 6,191 | 3,816 | 329,725,481 |
| Female Population | 48.1% | 50.0% | 50.5% |
| Male Population | 52.0% | 50.0% | 49.5% |
| Median Age | 48.2 | 44.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,183 | 3,440 | 309,327,143 |
| Population - 2000 | 4,493 | 2,869 | 285,036,114 |
| Population - 1990 | 2,530 | 2,129 | 251,960,433 |
| Pop. 2000 to Now | -1.8% | -8.0% | 15.6% |
| Pop. 1990 to Now | 74.4% | 24.0% | 30.8% |
| space4 | | | |
| Population Density | 560.2 | 301.4 | 93.4 |
| Land Area | 11.1 | 12.7 | 3,531,905.4 |
| Water Area | 1.0 | 2.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | North Sea, NY | Westhampton, NY | United States |
| Age 0 to 4 | 4.8% | 8.0% | 5.9% |
| Age 5 to 9 | 3.7% | 9.0% | 6.1% |
| Age 10 to 14 | 5.0% | 4.6% | 6.6% |
| Age 15 to 17 | 2.8% | 7.9% | 3.9% |
| Age 18 to 20 | 2.1% | 2.6% | 4.0% |
| Age 21 to 24 | 5.5% | 1.9% | 5.2% |
| Age 25 to 34 | 8.8% | 7.0% | 13.8% |
| Age 35 to 44 | 12.1% | 8.9% | 12.9% |
| Age 45 to 54 | 18.3% | 11.5% | 12.6% |
| Age 55 to 59 | 5.9% | 7.7% | 6.7% |
| Age 60 to 64 | 5.3% | 6.0% | 6.3% |
| Age 65 to 74 | 18.0% | 13.4% | 9.6% |
| Age 75 to 84 | 4.6% | 7.5% | 4.5% |
| Age 85 and over | 3.1% | 4.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | North Sea, NY | Westhampton, NY | United States |
| White | 69.3% | 80.5% | 59.4% |
| Black | 14.3% | 0.8% | 12.2% |
| Asian | 0.8% | 2.6% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 2.9% | 0.4% |
| Two or More Races | 2.9% | 4.9% | 3.2% |
| Hispanic | 12.8% | 8.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | North Sea, NY | Westhampton, NY | United States |
| Married Population | 50.9% | 60.2% | 49.8% |
| Currently Married | 50.6% | 59.6% | 48.0% |
| Married but Separated | 0.3% | 0.5% | 1.8% |
| Single Population | 49.1% | 39.8% | 50.2% |
| Never Married | 31.8% | 27.6% | 33.8% |
| Divorced | 9.2% | 6.2% | 10.8% |
| Widowed | 8.1% | 6.1% | 5.6% |
| space5 | | | |
| Household Size | 2.78 | 3.06 | 2.60 |
| Households | 2,226 | 1,193 | 124,010,992 |
| Family Households | 1,496 | 953 | 80,755,759 |
| Married couple, w/children | 29.7% | 37.0% | 30.5% |
| Married couple, no children | 49.1% | 52.3% | 42.9% |
| Non Family Households | 730 | 240 | 43,255,233 |
| Single householder, w/children | 7.2% | 6.2% | 15.8% |
| Single householder, no children | 14.1% | 4.5% | 10.8% |