# Counties in Colorado by median age on 1 July (US county estimates), 2025

All 64 values come from U.S. Census Bureau for 2025, so the places are comparable.

- Indicator id: `median_age_pep`
- Unit: years
- Definition: Age that divides the resident population of a US county into two halves of equal size on 1 July, from Census Bureau population estimates calculated by single year of age.
- Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage (https://www.census.gov/programs-surveys/popest/data/data-sets.html)
- Publisher page: https://invokely.ai/en/publishers/us-census-bureau
- Retrieved: 2026-10-12
- Citation: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/median-age-july-1-us-counties/colorado-counties

| Rank | Place | years |
|---:|---|---:|
| 1 | Custer County | 57.5 |
| 2 | Hinsdale County | 56.9 |
| 3 | Huerfano County | 56.4 |
| 4 | Mineral County | 55.7 |
| 5 | Ouray County | 55.5 |
| 6 | Teller County | 52 |
| 7 | Archuleta County | 51.5 |
| 7 | Jackson County | 51.5 |
| 9 | Costilla County | 50.7 |
| 10 | Park County | 50 |
| 11 | Clear Creek County | 49.4 |
| 12 | Gilpin County | 49.1 |
| 13 | Sedgwick County | 48.7 |
| 14 | Saguache County | 48.5 |
| 15 | Delta County | 48.4 |
| 16 | Las Animas County | 48 |
| 17 | Chaffee County | 47.9 |
| 18 | Dolores County | 47.8 |
| 19 | Montrose County | 46 |
| 20 | Fremont County | 45.5 |
| 21 | San Juan County | 45.3 |
| 22 | Montezuma County | 44.8 |
| 23 | Rio Grande County | 44.7 |
| 24 | Grand County | 44.5 |
| 25 | Baca County | 44.2 |
| 26 | Pitkin County | 44.1 |
| 27 | La Plata County | 43.8 |
| 28 | Elbert County | 43.6 |
| 28 | San Miguel County | 43.6 |
| 30 | Cheyenne County | 43.5 |
| 31 | Routt County | 43.2 |
| 32 | Kiowa County | 42.8 |
| 32 | Washington County | 42.8 |
| 34 | Mesa County | 42.1 |
| 35 | Crowley County | 41.9 |
| 35 | Otero County | 41.9 |
| 37 | Bent County | 41.7 |
| 38 | Pueblo County | 41.1 |
| 39 | Jefferson County | 40.8 |
| 40 | Rio Blanco County | 40.7 |
| 41 | Conejos County | 40.6 |
| 42 | Eagle County | 40.4 |
| 42 | Logan County | 40.4 |
| 44 | Kit Carson County | 40.3 |
| 45 | Phillips County | 40.2 |
| 46 | Douglas County | 40 |
| 46 | Moffat County | 40 |
| 48 | Lincoln County | 39.6 |
| 49 | Summit County | 39.5 |
| 50 | Boulder County | 38.8 |
| 51 | Broomfield County | 38.7 |
| 52 | Larimer County | 38.3 |
| 53 | Garfield County | 38.2 |
| 54 | Gunnison County | 37.9 |
| 55 | Yuma County | 37.5 |
| 56 | Arapahoe County | 37.4 |
| 56 | Prowers County | 37.4 |
| 58 | Lake County | 36.8 |
| 59 | Morgan County | 36.3 |
| 60 | El Paso County | 35.7 |
| 61 | Weld County | 35.3 |
| 62 | Adams County | 35.2 |
| 63 | Denver County | 35 |
| 64 | Alamosa County | 34.4 |