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

All 21 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/new-jersey-counties

| Rank | Place | years |
|---:|---|---:|
| 1 | Cape May County | 54 |
| 2 | Hunterdon County | 46.3 |
| 3 | Warren County | 44.1 |
| 4 | Sussex County | 43.7 |
| 5 | Monmouth County | 43.6 |
| 6 | Atlantic County | 43 |
| 7 | Morris County | 42.7 |
| 8 | Bergen County | 42.5 |
| 8 | Somerset County | 42.5 |
| 10 | Burlington County | 41.6 |
| 11 | Salem County | 41.5 |
| 12 | Ocean County | 40.7 |
| 13 | Gloucester County | 40.4 |
| 14 | Middlesex County | 39.6 |
| 15 | Camden County | 39.3 |
| 16 | Mercer County | 38.8 |
| 17 | Union County | 38.6 |
| 18 | Cumberland County | 37.8 |
| 18 | Passaic County | 37.8 |
| 20 | Essex County | 37.7 |
| 21 | Hudson County | 35.5 |