What are the fastest-growing counties in Colorado?
Elbert County is the fastest-growing county in Colorado: its population grew 3.10% a year from 2020 to 2025, to 30,534 residents (Census PEP Vintage 2025). Weld County (2.69%) and Douglas County (2.08%) follow. Colorado as a whole grew 0.77% a year to 6,012,561 residents.
Data as of 2026-09-23. Population, growth and migration: PEP Vintage 2025 · 2020–2025. Income migration: IRS SOI 2022–2023 (2-yr lag).
Top 10 counties in Colorado by population growth, 2020 to 2025
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Elbert County | 30,534 | 3.10% | +4,099 | +17 | +$40.4M |
| 2 | Weld County | 378,426 | 2.69% | +29,361 | +4,865 | +$244.2M |
| 3 | Douglas County | 399,396 | 2.08% | +25,508 | +4,692 | +$347.3M |
| 4 | Chaffee County | 20,831 | 1.34% | +1,369 | +57 | +$45.5M |
| 5 | Adams County | 554,668 | 1.28% | +2,744 | +17,217 | -$30.6M |
| 6 | Archuleta County | 14,306 | 1.28% | +996 | +54 | +$18.1M |
| 7 | Broomfield County | 79,174 | 1.23% | +2,460 | +1,417 | -$2.4M |
| 8 | Park County | 18,314 | 1.00% | +788 | +52 | +$20.4M |
| 9 | Larimer County | 377,292 | 0.95% | +11,855 | +3,716 | +$124.5M |
| 10 | Grand County | 16,496 | 0.93% | +284 | +291 | +$28.9M |
Where are people moving in Colorado?
Weld County gained the most people from elsewhere in the United States: net domestic migration of +29,361 from 2020 to 2025 (Census PEP Vintage 2025). The table ranks every Colorado place with 10,000 or more residents by that figure; the IRS column shows net adjusted gross income migration for 2022 to 2023.
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Weld County | 378,426 | 2.69% | +29,361 | +4,865 | +$244.2M |
| 2 | Douglas County | 399,396 | 2.08% | +25,508 | +4,692 | +$347.3M |
| 3 | Larimer County | 377,292 | 0.95% | +11,855 | +3,716 | +$124.5M |
| 4 | Mesa County | 162,845 | 0.86% | +7,964 | +490 | +$97.0M |
| 5 | Elbert County | 30,534 | 3.10% | +4,099 | +17 | +$40.4M |
| 6 | Pueblo County | 169,277 | 0.11% | +2,757 | +886 | -$8.1M |
| 7 | Adams County | 554,668 | 1.28% | +2,744 | +17,217 | -$30.6M |
| 8 | Fremont County | 50,039 | 0.47% | +2,604 | +51 | +$16.5M |
| 9 | Broomfield County | 79,174 | 1.23% | +2,460 | +1,417 | -$2.4M |
| 10 | Montrose County | 44,591 | 0.81% | +2,066 | +551 | +$30.6M |
Go past the headline numbers
The interactive Demographics map layer and the full report for a single place are part of paid plans.
Get the Demographics Report for Elbert CountyFrequently asked questions
- What are the fastest-growing counties in Colorado?
- By population growth from 2020 to 2025, the fastest are Elbert County (3.10% a year), Weld County (2.69% a year), Douglas County (2.08% a year), Chaffee County (1.34% a year) and Adams County (1.28% a year) (Census PEP Vintage 2025). Only places with 10,000 or more residents are ranked.
- Where are people moving in Colorado?
- By net domestic migration from 2020 to 2025, the largest gains are Weld County (+29,361), Douglas County (+25,508) and Larimer County (+11,855) (Census PEP Vintage 2025).
- How fast is Colorado growing overall?
- Colorado grew 0.77% a year from 2020 to 2025, to 6,012,561 residents, with net migration of +140,507 people (Census PEP Vintage 2025).
- Where does this Colorado data come from, and how current is it?
- Population, growth and migration come from the U.S. Census Bureau Population Estimates Program (PEP Vintage 2025 · 2020–2025). Income migration comes from IRS Statistics of Income (IRS SOI 2022–2023 (2-yr lag)). Counties with fewer than 10,000 residents are not ranked (27 of 64 in Colorado). Data last loaded 2026-09-23.
Data as of 2026-09-23: sources and periods
- Population, growth and migration
- U.S. Census Bureau, Population Estimates Program: PEP Vintage 2025 · 2020–2025. census.gov/programs-surveys/popest
- Income migration (net AGI)
- Internal Revenue Service, Statistics of Income migration data: IRS SOI 2022–2023 (2-yr lag). irs.gov/statistics/soi-tax-stats-migration-data
How to read the table
- Population is the Census July 1 estimate of the latest vintage.
- Growth is the compound annual rate over 2020 to 2025.
- Net domestic and international migration are cumulative people over 2020 to 2025.
- IRS net AGI migration is adjusted gross income that moved in, less what moved out, for 2022 to 2023. A plus sign means a net inflow.
- Places with fewer than 10,000 residents are left out of the rankings.