| | Yuba City, CA | Twain Harte, CA | United States |
| Population | 69,540 | 2,471 | 329,725,481 |
| Female Population | 50.3% | 41.9% | 50.5% |
| Male Population | 49.7% | 58.1% | 49.5% |
| Median Age | 35.4 | 52.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 65,615 | 2,262 | 309,327,143 |
| Population - 2000 | 36,758 | 2,586 | 285,036,114 |
| Population - 1990 | 27,437 | 2,170 | 251,960,433 |
| Pop. 2000 to Now | 80.8% | 6.0% | 15.6% |
| Pop. 1990 to Now | 142.2% | 26.3% | 30.8% |
| space4 | | | |
| Population Density | 4,667.1 | 668.0 | 93.4 |
| Land Area | 14.9 | 3.7 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Yuba City, CA | Twain Harte, CA | United States |
| Age 0 to 4 | 6.3% | 6.1% | 5.9% |
| Age 5 to 9 | 7.1% | 3.9% | 6.1% |
| Age 10 to 14 | 7.4% | 3.0% | 6.6% |
| Age 15 to 17 | 4.6% | 1.3% | 3.9% |
| Age 18 to 20 | 4.1% | 1.7% | 4.0% |
| Age 21 to 24 | 5.6% | 4.7% | 5.2% |
| Age 25 to 34 | 14.4% | 17.0% | 13.8% |
| Age 35 to 44 | 12.0% | 8.6% | 12.9% |
| Age 45 to 54 | 11.7% | 10.5% | 12.6% |
| Age 55 to 59 | 5.4% | 7.4% | 6.7% |
| Age 60 to 64 | 6.2% | 10.5% | 6.3% |
| Age 65 to 74 | 8.7% | 17.2% | 9.6% |
| Age 75 to 84 | 4.6% | 6.4% | 4.5% |
| Age 85 and over | 1.9% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Yuba City, CA | Twain Harte, CA | United States |
| White | 41.1% | 83.0% | 59.4% |
| Black | 2.1% | 0.0% | 12.2% |
| Asian | 19.1% | 1.2% | 5.6% |
| Native American | 1.0% | 0.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.0% | 0.2% |
| Other | 0.8% | 0.0% | 0.4% |
| Two or More Races | 4.8% | 2.1% | 3.2% |
| Hispanic | 30.9% | 13.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Yuba City, CA | Twain Harte, CA | United States |
| Married Population | 51.9% | 60.4% | 49.8% |
| Currently Married | 49.5% | 58.3% | 48.0% |
| Married but Separated | 2.4% | 2.1% | 1.8% |
| Single Population | 48.1% | 39.6% | 50.2% |
| Never Married | 31.2% | 21.7% | 33.8% |
| Divorced | 10.9% | 12.5% | 10.8% |
| Widowed | 6.1% | 5.5% | 5.6% |
| space5 | | | |
| Household Size | 2.94 | 2.20 | 2.60 |
| Households | 23,398 | 1,121 | 124,010,992 |
| Family Households | 16,340 | 706 | 80,755,759 |
| Married couple, w/children | 36.0% | 29.7% | 30.5% |
| Married couple, no children | 34.4% | 61.0% | 42.9% |
| Non Family Households | 7,058 | 415 | 43,255,233 |
| Single householder, w/children | 18.0% | 2.1% | 15.8% |
| Single householder, no children | 11.6% | 7.1% | 10.8% |