Star and Kuna Lead Dramatic Population Growth Across Idaho’s Treasure Valley
Two of Idaho’s smaller rural communities are outpacing their larger neighbors by a wide margin, according to new population estimates released by the Community Planning Association of Southwest Idaho. Star and Kuna — both located in the rapidly expanding Treasure Valley — each grew by more than 10% between 2025 and 2026, making them the fastest-growing communities in Ada and Canyon counties at a time when the region’s combined population is closing in on the 1 million mark.
By the Numbers: Star and Kuna Surge Ahead
According to COMPASS, which compiles annual population estimates using the most recent decennial Census as a baseline and factors in local building permits, household sizes, vacancy rates, and annexations, Star grew by 23.6% in the last year — adding more than 5,200 residents to reach a total population of 27,660. Just one year prior, Star’s population stood at 22,370.
The small town, which straddles both Ada and Canyon counties, has seen particularly dramatic growth on its Canyon County side. According to COMPASS data, Star’s Canyon County population has grown from just 10 residents in 2021 to 710 in 2026 — a sign that new development and subdivision construction is actively pushing the town’s footprint south and west. New subdivisions are under construction on the north side of Star, and businesses — some recently opened, others still under construction — now line State Street.
Kuna, located to the south in Ada County, was not far behind. The community grew by 14.3% year over year, climbing from 33,750 residents to 38,560. That gain of nearly 4,810 people in a single year reflects continued demand for housing in communities offering more affordable land and a quieter lifestyle than Boise or Meridian while still providing access to Treasure Valley employment centers.
How Boise, Meridian, and Other Cities Compare
By contrast, Idaho’s most-populous cities grew at a much slower pace. Boise, Meridian, and Nampa averaged a combined growth rate of just 2.4%, with Meridian growing at 3.2% and Boise at 1.1%. Caldwell led the larger cities with a 6.6% growth rate. Middleton also posted notable growth at 8.8%, rising from 13,970 to 15,110 residents.
In raw numbers, Caldwell and Meridian ranked highest for total individuals added — gaining 5,160 and 4,730 new residents, respectively — underscoring that percentage growth and numeric growth tell different parts of the same story.
“While our population growth is spread throughout the region, the percentage of growth in some of our smaller communities is staggering,” said Austin Miller, COMPASS Planning Team Lead, in a statement accompanying the new data release.
Miller also emphasized the value of looking at growth from multiple angles. “These distinctions underscore the importance of looking at the data from multiple viewpoints, such as numeric growth, percent growth, change year-over-year, and change as compared to the most recent Census count,” Miller said. “Each of these provides insight into how we are growing and helps COMPASS and the individual jurisdictions plan for the future.”
Impact on Ada County Residents and Taxpayers
Ada County’s total population now stands at an estimated 589,500, with Canyon County at 287,260 — a combined total of 876,760 across the two counties. That figure represents a jump from 847,840 just one year ago, and a dramatic increase from 726,072 in 2020 and 581,298 in 2010. When COMPASS included Boise and Elmore counties in its calculations, the four-county regional total reached 915,940.
For Ada County residents, rapid growth in communities like Star and Kuna carries real consequences. Demand for roads, schools, emergency services, water infrastructure, and parks must keep pace with the influx of new households. Local governments in these smaller communities are now tasked with planning and funding the infrastructure necessary to support populations that are growing at rates few municipalities anywhere in the country can match. Readers interested in how Boise’s established neighborhoods are evolving may want to explore recent improvements to the Julia Davis Park Rose Garden or learn more about Boise’s history and growth through America 250 short histories.
What Comes Next
COMPASS updates its population estimates annually as of April 1, meaning the next round of data will reflect growth through early 2027. Local governments and regional planners rely on these figures to guide zoning decisions, infrastructure investments, school capacity planning, and transportation corridors.
Residents who want to review the full COMPASS population report — including breakdowns by city and county — can access it at compassidaho.org. Community members in Star, Kuna, and surrounding areas are encouraged to attend local planning and city council meetings to stay informed about how their communities are managing this extraordinary pace of growth.