County facts · Population growth · October 23, 2026
Fastest Growing Counties in Arizona, 2020 to 2025
Arizona's fastest growing counties by percent and by people added, April 2020 to July 2025 Census estimates, with each official parcel map.
Looking for the fastest growing counties in Arizona? From the Census Bureau's April 1, 2020 estimates base to its July 1, 2025 estimate, Arizona went from about 7,158,104 to 7,623,818 residents, a change of +465,714 (+6.5%). The fastest growing county by percentage was Pinal County (+26.6%), while Maricopa County added the most people (+264,256, +6.0%).
Every row below links to the county's Platbookmapper page and straight to its official parcel viewer, handy if growth is why you are looking at land there.
Arizona growth at a glance
- County: 15
- Statewide, April 2020 to July 2025: +465,714 residents (+6.5%); July 2024 to July 2025 alone: +67,394 (+0.9%)
- Grew: 12 of 15 · Lost residents: 3
- Fastest growing by percent: Pinal County (+26.6%); most people added: Maricopa County (+264,256)
- Counties with more deaths than births over the period: 8 of 15
The 10 fastest growing Arizona counties by percent
| # | County | Apr 2020 | Jul 2025 | Change | % change | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Pinal County | 425,993 | 539,380 | +113,387 | +26.6% | ArcGIS Experience Builder |
| 2 | Yuma County | 205,006 | 224,449 | +19,443 | +9.5% | ArcGIS Experience Builder |
| 3 | Mohave County | 213,261 | 228,102 | +14,841 | +7.0% | county web map |
| 4 | Yavapai County | 236,210 | 252,552 | +16,342 | +6.9% | ArcGIS Experience Builder |
| 5 | Maricopa County | 4,425,302 | 4,689,558 | +264,256 | +6.0% | county web map |
| 6 | Santa Cruz County | 47,669 | 50,020 | +2,351 | +4.9% | ArcGIS Map Viewer |
| 7 | Graham County | 38,538 | 40,157 | +1,619 | +4.2% | ArcGIS Experience Builder |
| 8 | Navajo County | 106,712 | 109,946 | +3,234 | +3.0% | county web map |
| 9 | Pima County | 1,043,431 | 1,074,685 | +31,254 | +3.0% | county web map |
| 10 | Gila County | 53,268 | 53,801 | +533 | +1.0% | ArcGIS Web AppBuilder |
These 10 added about 467,260 people combined. The median county changed by +3.0%.
The 10 counties that added the most people
| # | County | People added | % change | Jul 2025 | Parcel viewer |
|---|---|---|---|---|---|
| 1 | Maricopa County | +264,256 | +6.0% | 4,689,558 | county web map |
| 2 | Pinal County | +113,387 | +26.6% | 539,380 | ArcGIS Experience Builder |
| 3 | Pima County | +31,254 | +3.0% | 1,074,685 | county web map |
| 4 | Yuma County | +19,443 | +9.5% | 224,449 | ArcGIS Experience Builder |
| 5 | Yavapai County | +16,342 | +6.9% | 252,552 | ArcGIS Experience Builder |
| 6 | Mohave County | +14,841 | +7.0% | 228,102 | county web map |
| 7 | Navajo County | +3,234 | +3.0% | 109,946 | county web map |
| 8 | Santa Cruz County | +2,351 | +4.9% | 50,020 | ArcGIS Map Viewer |
| 9 | Graham County | +1,619 | +4.2% | 40,157 | ArcGIS Experience Builder |
| 10 | Cochise County | +892 | +0.7% | 126,332 | ArcGIS Web AppBuilder |
The top 10 account for about 100% of all the gains in the counties that grew.
Where the new residents came from
The Census Bureau splits each change into natural change (births minus deaths), net domestic migration (moves from other parts of the US) and net international migration. Totals for April 2020 to July 2025 in the five fastest growing counties:
| County | Births minus deaths | Net domestic moves | Net international moves | Total change |
|---|---|---|---|---|
| Pinal County | +3,910 | +99,661 | +9,845 | +113,387 |
| Yuma County | +4,307 | +4,568 | +10,339 | +19,443 |
| Mohave County | −12,640 | +26,999 | +422 | +14,841 |
| Yavapai County | −10,803 | +26,246 | +1,220 | +16,342 |
| Maricopa County | +51,454 | +95,474 | +117,913 | +264,256 |
In 3 of these 5, moves from elsewhere in the US were the biggest source of growth. The three parts do not add up exactly to the total because the Census Bureau also carries a small residual.
The last year alone: July 2024 to July 2025
- Pinal County: +4.6% (+23,654)
- Yuma County: +1.4% (+3,061)
- Cochise County: +0.9% (+1,133)
- Mohave County: +0.8% (+1,840)
- Maricopa County: +0.8% (+35,411)
4 of these 5 are also in the 2020–2025 top 10, so the growth is not a one-year blip.
Counties losing residents
3 of Arizona's 15 counties had fewer residents in July 2025 than in April 2020. They are:
- Greenlee County: −2.6% (−252, now about 9,312)
- Apache County: −2.4% (−1,600, now about 64,445)
- Coconino County: −0.5% (−743, now about 144,368)
What fast growth means on a parcel map
- New lots show up as plats first. When land is subdivided, the plat is recorded with the county and the parcel layer catches up on its own schedule, so a brand-new lot may not appear on the map for a while. Check the recorder's recent plats if a parcel looks missing.
- Parcel numbers change after splits. A tract that was one parcel last year can be several today. Search by owner name or address as well as by an old parcel number.
- City limits move. Growing cities annex land, which changes who handles zoning and permits even though the county still keeps the deed and the tax map.
- Percent is not the same as people. A small county can post a big percentage on a modest number of new residents, so read the people-added column too.
Related guides
- Largest counties in Arizona
- Arizona county GIS websites by viewer
- Arizona plat maps
- Arizona landowner maps for hunting
- Fastest growing counties in the US
- US counties losing population
More: All Arizona counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Percent change is from the April 1, 2020 estimates base to the July 1, 2025 estimate.
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 23, 2026) for each official parcel viewer.