Demographics & People — Jefferson, Iowa
Population Overview
| Population (Census) | 4,164 |
| Estimated 2026 | ~4,100 |
| Median Age | 53.6 |
| Total Households | 2,108 |
| Family Households | 1,091 |
| Average Household Size | 1.92 |
| Diversity Index | 0.0976 (relatively homogeneous) |
Race & Ethnicity
| White | 3,904 |
| Black or African American | 12 |
| Asian | 0 |
| Hispanic or Latino | 199 |
Heritage & Ancestry
| Group | Count |
| German | 1,577 |
| Unclassified or not reported | 1,107 |
| English | 881 |
| Irish | 541 |
| Other groups | 318 |
| Norwegian | 281 |
| Hispanic: Hispanic or Latino | 213 |
| French (except Basque) | 153 |
| Dutch | 140 |
| American | 139 |
Language
| English Only | 3,828 |
| Spanish | 117 |
| Population 5+ | 3,972 |
Veterans
| Veterans | 259 |
| Population 18+ | 3,371 |
Source: Census ACS 5-Year 2023; Census ACS 5-Year 2023, Table B01003; Census ACS 5-Year 2023, B19013. Data for Jefferson, Iowa.