| | Watertown, MN | Sanford, FL | United States |
| Population | 4,659 | 60,215 | 329,725,481 |
| Female Population | 50.7% | 49.2% | 50.5% |
| Male Population | 49.3% | 50.8% | 49.5% |
| Median Age | 32.4 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,224 | 53,964 | 309,327,143 |
| Population - 2000 | 3,029 | 38,291 | 285,036,114 |
| Population - 1990 | 2,408 | 32,387 | 251,960,433 |
| Pop. 2000 to Now | 52.1% | 60.6% | 15.6% |
| Pop. 1990 to Now | 91.4% | 89.9% | 30.8% |
| space4 | | | |
| Population Density | 1,774.2 | 2,592.4 | 93.4 |
| Land Area | 2.6 | 23.2 | 3,531,905.4 |
| Water Area | 0.0 | 3.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Watertown, MN | Sanford, FL | United States |
| Age 0 to 4 | 11.1% | 6.4% | 5.9% |
| Age 5 to 9 | 12.2% | 7.3% | 6.1% |
| Age 10 to 14 | 4.0% | 6.6% | 6.6% |
| Age 15 to 17 | 2.0% | 3.0% | 3.9% |
| Age 18 to 20 | 3.1% | 2.5% | 4.0% |
| Age 21 to 24 | 6.2% | 5.9% | 5.2% |
| Age 25 to 34 | 13.9% | 19.2% | 13.8% |
| Age 35 to 44 | 12.3% | 14.6% | 12.9% |
| Age 45 to 54 | 13.0% | 11.2% | 12.6% |
| Age 55 to 59 | 7.6% | 5.2% | 6.7% |
| Age 60 to 64 | 7.8% | 5.8% | 6.3% |
| Age 65 to 74 | 5.0% | 7.9% | 9.6% |
| Age 75 to 84 | 1.3% | 2.6% | 4.5% |
| Age 85 and over | 0.5% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Watertown, MN | Sanford, FL | United States |
| White | 94.2% | 38.5% | 59.4% |
| Black | 0.0% | 27.3% | 12.2% |
| Asian | 0.0% | 3.3% | 5.6% |
| Native American | 0.3% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 0.9% | 3.8% | 3.2% |
| Hispanic | 4.6% | 26.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Watertown, MN | Sanford, FL | United States |
| Married Population | 62.2% | 43.1% | 49.8% |
| Currently Married | 61.9% | 41.0% | 48.0% |
| Married but Separated | 0.3% | 2.2% | 1.8% |
| Single Population | 37.8% | 56.9% | 50.2% |
| Never Married | 30.5% | 38.1% | 33.8% |
| Divorced | 5.5% | 12.8% | 10.8% |
| Widowed | 1.8% | 6.0% | 5.6% |
| space5 | | | |
| Household Size | 2.90 | 2.61 | 2.60 |
| Households | 1,589 | 22,616 | 124,010,992 |
| Family Households | 1,298 | 14,052 | 80,755,759 |
| Married couple, w/children | 32.8% | 30.1% | 30.5% |
| Married couple, no children | 47.3% | 33.7% | 42.9% |
| Non Family Households | 291 | 8,564 | 43,255,233 |
| Single householder, w/children | 15.9% | 23.6% | 15.8% |
| Single householder, no children | 4.0% | 12.6% | 10.8% |