Idaho local data guide

Treasure Valley City Annual Growth Rates (2025–2026)

According to the Community Planning Association of Southwest Idaho (COMPASS) 2026 Population Estimates, the Treasure Valley's overall expansion is led by sharp percentage surges in outer suburbs like Star and Kuna, while larger regional centers like Meridian maintain steady numeric additions.

Updated with grounded research as of 2026-07-29.

The short answer

According to the COMPASS 2026 Population Estimates released in April 2026, single-year growth rates for Treasure Valley cities range from 14% to 14.7% in outer suburbs such as Star and Kuna, down to 3% to 3.2% in larger employment hubs like Meridian.

Key facts

Star Annual Growth Rate
14% to 14.7% year-over-year (COMPASS 2026 Population Estimates)
Kuna Annual Growth Rate
14% to 14.2% year-over-year (COMPASS 2026 Population Estimates)
Meridian Annual Growth Rate
3% to 3.2% year-over-year (COMPASS 2026 Population Estimates)
Ada County Overall Growth Rate
2.0% annual increase, adding 10,916 residents in 2025 (U.S. Census Bureau / Idaho Dept. of Labor)

Suburban Percentage Surges in Kuna and Star

The April 2026 population report from COMPASS highlights how smaller suburban municipalities in Ada and Canyon counties are experiencing elevated percentage growth rates relative to their base populations. In single-year estimates covering 2025–2026, Star recorded an annual growth rate of 14% to 14.7%, while Kuna expanded by 14% to 14.2%. These figures reflect significant single-family home development, greenfield master-planned communities, and active municipal annexations along the peripheral corridors of the Boise metropolitan area.

  • Star's annual growth rate reached approximately 14.7% (COMPASS 2026), making it one of the fastest-growing cities in Southwest Idaho by percentage since 2020.
  • Kuna grew by roughly 14.2% year-over-year (COMPASS 2026), adding 4,810 residents in a single year to reach a population of 38,560.

Steady Growth in Established Regional Hubs Like Meridian

Larger, established municipalities in Ada County continue to add substantial volume, even as their baseline population sizes compress their percentage growth rates. Meridian logged a 3.0% to 3.2% annual growth rate according to COMPASS 2026 estimates. Despite a smaller percentage jump than Kuna or Star, Meridian remains one of the primary drivers of raw population gains in the Treasure Valley, adding 4,730 residents over the same period.

  • Meridian's annual growth rate stands at 3% to 3.2% year-over-year (COMPASS 2026).
  • Raw numeric gains in Meridian (4,730 residents) remain nearly equal to those in Kuna (4,810 residents), demonstrating the operational difference between volume and rate metrics.

County-Level Context and Methodological Differences

Regional and county-level data provide broader context for local municipal expansion. Figures released by the U.S. Census Bureau and reported by the Idaho Department of Labor in March 2026 show that Ada County grew by 2.0% in 2025, adding 10,916 residents, while adjacent Canyon County grew by 2.9% (7,679 residents). Analysts note that COMPASS municipal estimates utilize housing permit construction data and annexation records, whereas federal Census estimates rely primarily on post-censal administrative records and migration metrics, leading to slight variations between datasets.

  • Ada County overall grew by 2.0% annually, reaching nearly 550,000 residents in 2025 (U.S. Census Bureau / Idaho Dept. of Labor).
  • Canyon County grew by 2.9% annually in 2025, buoyed by expanding residential inventory in Caldwell and Nampa.

Common questions

Why are percentage growth rates so much higher in Star and Kuna than in Meridian?

Percentage growth calculation is sensitive to baseline population size. Because Kuna and Star started with smaller base populations, adding several thousand new housing units results in a high percentage jump (14%–14.7%). Meridian has a much larger existing population base, so adding a similar number of new residents yields a lower percentage increase (3%–3.2%).

How does COMPASS calculate local population growth for Treasure Valley cities?

COMPASS calculates annual population estimates as of April 1 each year by taking the most recent decennial U.S. Census baseline and adjusting for local residential building permits, household size factors, vacancy rates, and recent municipal annexations.

What is Ada County's overall growth rate compared to individual city growth?

According to U.S. Census Bureau estimates compiled by the Idaho Department of Labor in March 2026, Ada County grew by 2.0% overall in 2025. Individual city growth rates vary widely around that county average, ranging from roughly 1% in Boise to over 14% in Star and Kuna.

Related Idaho questions

  • How does numeric growth compare to percentage growth across Ada and Canyon counties?
  • What are the long-term regional population projections for the Treasure Valley through 2040 and 2050?
  • How are local infrastructure and school districts planning for rapid growth in Kuna and Star?

Sources and verification