| | Streator, IL | Byron, IL | United States |
| Population | 12,135 | 3,740 | 329,725,481 |
| Female Population | 50.8% | 52.6% | 50.5% |
| Male Population | 49.2% | 47.4% | 49.5% |
| Median Age | 40.5 | 35.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,973 | 3,833 | 309,327,143 |
| Population - 2000 | 14,190 | 2,917 | 285,036,114 |
| Population - 1990 | 14,121 | 2,284 | 251,960,433 |
| Pop. 2000 to Now | -8.9% | 25.1% | 15.6% |
| Pop. 1990 to Now | -8.4% | 59.8% | 30.8% |
| space4 | | | |
| Population Density | 1,752.1 | 1,046.5 | 93.4 |
| Land Area | 6.9 | 3.6 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Streator, IL | Byron, IL | United States |
| Age 0 to 4 | 5.4% | 8.9% | 5.9% |
| Age 5 to 9 | 4.0% | 7.6% | 6.1% |
| Age 10 to 14 | 5.5% | 7.8% | 6.6% |
| Age 15 to 17 | 3.8% | 3.1% | 3.9% |
| Age 18 to 20 | 4.0% | 4.5% | 4.0% |
| Age 21 to 24 | 7.7% | 5.8% | 5.2% |
| Age 25 to 34 | 12.6% | 11.2% | 13.8% |
| Age 35 to 44 | 12.9% | 16.8% | 12.9% |
| Age 45 to 54 | 9.2% | 11.3% | 12.6% |
| Age 55 to 59 | 6.8% | 3.4% | 6.7% |
| Age 60 to 64 | 7.6% | 4.8% | 6.3% |
| Age 65 to 74 | 10.8% | 7.9% | 9.6% |
| Age 75 to 84 | 5.8% | 4.9% | 4.5% |
| Age 85 and over | 3.9% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Streator, IL | Byron, IL | United States |
| White | 79.1% | 84.3% | 59.4% |
| Black | 3.3% | 0.8% | 12.2% |
| Asian | 1.9% | 1.3% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.7% | 5.2% | 3.2% |
| Hispanic | 14.0% | 8.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Streator, IL | Byron, IL | United States |
| Married Population | 40.1% | 46.2% | 49.8% |
| Currently Married | 38.9% | 45.9% | 48.0% |
| Married but Separated | 1.2% | 0.3% | 1.8% |
| Single Population | 59.9% | 53.8% | 50.2% |
| Never Married | 34.6% | 25.7% | 33.8% |
| Divorced | 15.9% | 15.5% | 10.8% |
| Widowed | 9.5% | 12.5% | 5.6% |
| space5 | | | |
| Household Size | 2.08 | 2.45 | 2.60 |
| Households | 5,733 | 1,487 | 124,010,992 |
| Family Households | 2,886 | 881 | 80,755,759 |
| Married couple, w/children | 21.2% | 34.8% | 30.5% |
| Married couple, no children | 42.4% | 32.1% | 42.9% |
| Non Family Households | 2,847 | 606 | 43,255,233 |
| Single householder, w/children | 25.8% | 14.3% | 15.8% |
| Single householder, no children | 10.6% | 18.7% | 10.8% |