| | Haleiwa, HI | Nassau, NY | United States |
| Population | 4,651 | 4,616 | 329,725,481 |
| Female Population | 49.1% | 45.7% | 50.5% |
| Male Population | 50.9% | 54.3% | 49.5% |
| Median Age | 42.2 | 42.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,023 | 4,783 | 309,327,143 |
| Population - 2000 | 2,225 | 4,818 | 285,036,114 |
| Population - 1990 | 2,442 | 4,989 | 251,960,433 |
| Pop. 2000 to Now | 58.3% | -1.6% | 15.6% |
| Pop. 1990 to Now | 44.3% | -4.9% | 30.8% |
| space4 | | | |
| Population Density | 2,037.2 | 103.9 | 93.4 |
| Land Area | 2.3 | 44.4 | 3,531,905.4 |
| Water Area | 0.7 | 0.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Haleiwa, HI | Nassau, NY | United States |
| Age 0 to 4 | 4.8% | 5.9% | 5.9% |
| Age 5 to 9 | 6.8% | 6.5% | 6.1% |
| Age 10 to 14 | 4.2% | 4.8% | 6.6% |
| Age 15 to 17 | 2.6% | 3.4% | 3.9% |
| Age 18 to 20 | 2.0% | 4.9% | 4.0% |
| Age 21 to 24 | 1.6% | 2.1% | 5.2% |
| Age 25 to 34 | 15.2% | 15.0% | 13.8% |
| Age 35 to 44 | 15.8% | 10.9% | 12.9% |
| Age 45 to 54 | 11.1% | 14.0% | 12.6% |
| Age 55 to 59 | 7.2% | 4.7% | 6.7% |
| Age 60 to 64 | 7.3% | 9.3% | 6.3% |
| Age 65 to 74 | 14.6% | 11.3% | 9.6% |
| Age 75 to 84 | 5.4% | 6.4% | 4.5% |
| Age 85 and over | 1.4% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Haleiwa, HI | Nassau, NY | United States |
| White | 27.8% | 94.2% | 59.4% |
| Black | 1.2% | 0.0% | 12.2% |
| Asian | 25.5% | 0.6% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 12.3% | 0.0% | 0.2% |
| Other | 0.2% | 0.3% | 0.4% |
| Two or More Races | 21.6% | 2.1% | 3.2% |
| Hispanic | 11.5% | 2.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Haleiwa, HI | Nassau, NY | United States |
| Married Population | 42.7% | 58.3% | 49.8% |
| Currently Married | 42.2% | 57.1% | 48.0% |
| Married but Separated | 0.5% | 1.2% | 1.8% |
| Single Population | 57.3% | 41.7% | 50.2% |
| Never Married | 37.0% | 26.0% | 33.8% |
| Divorced | 12.1% | 11.9% | 10.8% |
| Widowed | 8.2% | 3.8% | 5.6% |
| space5 | | | |
| Household Size | 3.00 | 2.48 | 2.60 |
| Households | 1,548 | 1,864 | 124,010,992 |
| Family Households | 1,010 | 1,288 | 80,755,759 |
| Married couple, w/children | 32.4% | 27.8% | 30.5% |
| Married couple, no children | 36.6% | 54.3% | 42.9% |
| Non Family Households | 538 | 576 | 43,255,233 |
| Single householder, w/children | 10.6% | 12.7% | 15.8% |
| Single householder, no children | 20.4% | 5.2% | 10.8% |