Idaho added 28,900 residents between 2024 and 2025, marking a 1.4% annual increase that outpaced every other state in the nation. According to population data published by USAFacts and updated July 6, 2026, the growth was primarily driven by people moving from other states. That single-year population gain is larger than the entire population of Moscow, Idaho, and continues a decade-long surge that's reshaped the state's demographics.
The numbers show Idaho's growth has been relentless. Since 2000, the state's population increased every single year for 25 consecutive years. The largest jump came between 2020 and 2021, when Idaho gained 55,500 residents. The smallest 21st-century increase occurred between 2011 and 2012, when the state added 13,700 people. Over the full decade from 2015 to 2025, Idaho's population grew by 22%, compared to just 6.2% for the US as a whole. That performance ranked Idaho first among all states in population growth over that ten-year period. At the county level, Ada County led in raw numbers, welcoming 10,916 new residents, while Canyon County posted the fastest growth rate at 2.9%. Blaine County was the only county to shrink, losing 184 residents, and Power County saw a 1% decline.
The report breaks down Idaho's 28,900-person increase into three components. Natural population change—births minus deaths—contributed 6,900 people, as births exceeded deaths. International immigration added about 2,100 residents, representing people who moved to Idaho from other countries. But the biggest driver was domestic migration: roughly 19,900 more people moved to Idaho from other states than left. The report finds that changes in population reflect "birth and death rates, immigration patterns, regional shifts, and even the overall health of the economy."
Idaho's explosive growth reflects broader national migration trends, with people leaving high-cost coastal states for more affordable interior markets. The fact that domestic migration accounted for nearly 69% of the state's population gain shows Idaho is winning the competition for residents fleeing other states. Natural population growth and international immigration played supporting roles, but the story is fundamentally about Americans choosing Idaho over their current homes. The concentration of growth in Ada and Canyon counties—home to Boise and Nampa—suggests new arrivals are clustering in the state's urban corridors rather than spreading evenly across its rural landscape. With 25 straight years of growth and the nation's fastest decade-long expansion rate, Idaho has transformed from a quiet Western outpost into one of America's hottest destinations.
The state's growth trajectory shows no signs of slowing. Idaho has now ranked first in the nation for population growth over the past decade, a distinction that reflects sustained appeal rather than a temporary spike. With domestic migration continuing to fuel the majority of new arrivals, Idaho's population will likely keep climbing as long as housing remains more affordable than coastal alternatives and jobs follow people westward. The bottom line: Idaho isn't just growing—it's leading the pack.