| Place Name | Jefferson |
| Place Type | City |
| ZIP Code(s) | 50129 |
| County | Greene County |
| Area Code(s) | 515 |
| Timezone | Central Daylight Time (CDT) |
| Population (2022) | 4,329 |
| Population Growth Rate (2010-19) | -3.75% |
| Majority Ethnicity | White 94.79% |
| US Congressional District(s) | Iowa 4th |
| State House Districts | 47 |
| State Senate Districts | 24 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 94.79% |
| African American | 0.48% |
| Hispanic | 0% |
| Asian | 0.38% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 4.35% |