| | Rocky Ford, CO | Arnold, MO | United States |
| Population | 3,876 | 20,808 | 329,725,481 |
| Female Population | 48.6% | 50.8% | 50.5% |
| Male Population | 51.4% | 49.2% | 49.5% |
| Median Age | 36.7 | 42.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,965 | 20,875 | 309,327,143 |
| Population - 2000 | 4,286 | 19,965 | 285,036,114 |
| Population - 1990 | 4,162 | 18,828 | 251,960,433 |
| Pop. 2000 to Now | -11.2% | 5.9% | 15.6% |
| Pop. 1990 to Now | -8.6% | 12.3% | 30.8% |
| space4 | | | |
| Population Density | 2,333.5 | 1,796.4 | 93.4 |
| Land Area | 1.7 | 11.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Rocky Ford, CO | Arnold, MO | United States |
| Age 0 to 4 | 5.7% | 5.7% | 5.9% |
| Age 5 to 9 | 7.2% | 5.8% | 6.1% |
| Age 10 to 14 | 7.1% | 5.4% | 6.6% |
| Age 15 to 17 | 3.8% | 4.8% | 3.9% |
| Age 18 to 20 | 7.6% | 2.8% | 4.0% |
| Age 21 to 24 | 6.9% | 2.8% | 5.2% |
| Age 25 to 34 | 10.4% | 14.9% | 13.8% |
| Age 35 to 44 | 11.7% | 11.0% | 12.9% |
| Age 45 to 54 | 12.0% | 12.6% | 12.6% |
| Age 55 to 59 | 4.6% | 8.3% | 6.7% |
| Age 60 to 64 | 6.5% | 7.5% | 6.3% |
| Age 65 to 74 | 8.5% | 10.3% | 9.6% |
| Age 75 to 84 | 5.7% | 6.0% | 4.5% |
| Age 85 and over | 2.3% | 2.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Rocky Ford, CO | Arnold, MO | United States |
| White | 37.1% | 90.4% | 59.4% |
| Black | 0.1% | 0.4% | 12.2% |
| Asian | 1.1% | 0.6% | 5.6% |
| Native American | 0.4% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 2.5% | 6.0% | 3.2% |
| Hispanic | 58.7% | 2.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Rocky Ford, CO | Arnold, MO | United States |
| Married Population | 39.4% | 53.4% | 49.8% |
| Currently Married | 36.5% | 50.5% | 48.0% |
| Married but Separated | 2.9% | 2.9% | 1.8% |
| Single Population | 60.6% | 46.6% | 50.2% |
| Never Married | 34.2% | 25.8% | 33.8% |
| Divorced | 13.5% | 13.4% | 10.8% |
| Widowed | 12.9% | 7.4% | 5.6% |
| space5 | | | |
| Household Size | 2.93 | 2.46 | 2.60 |
| Households | 1,298 | 8,405 | 124,010,992 |
| Family Households | 813 | 5,530 | 80,755,759 |
| Married couple, w/children | 27.1% | 30.9% | 30.5% |
| Married couple, no children | 36.5% | 43.2% | 42.9% |
| Non Family Households | 485 | 2,875 | 43,255,233 |
| Single householder, w/children | 15.4% | 17.8% | 15.8% |
| Single householder, no children | 21.0% | 8.0% | 10.8% |