IDAHO FALLS, Idaho (KIFI) - Newly released data from the U.S. Census Bureau shows Idaho’s population growth from 2020 to 2021 was well dispersed around the state, with every Idaho county growing in population over the year.
The Census Bureau reported the state’s population rose from 1,847,772 in 2020, to 1,900,923 in 2021, in its July 1, 2021, population estimates. The newest data release shows how the population growth was distributed around the state.
While the largest numerical growth was concentrated in urban counties, most of Idaho’s rural counties experienced proportional growth. In all, 38 of Idaho’s 44 counties grew by at least 1%, and every county grew faster than the national average growth rate, except for the Clark County, which is Idaho’s least populous county.
Population growth continued to be strong in Idaho’s three largest counties – Ada, Canyon and Kootenai – from 2020 to 2021. These three counties collectively accounted for just under 50% of the state’s total population, and they accounted for 31,491 of the state’s new residents, or 59% of the population growth. Ada County’s population exceeded half a million for the first time, growing to 511,931.
Despite the continued trend toward urbanization, several rural Idaho counties showed significant growth, with six rural counties growing by faster than 4%. Boise County was the fastest-growing county at 5.8%.
Net migration is the main driver of Idaho’s growth, primarily from other states rather than foreign countries. Natural growth (the difference between births and deaths) remains very low for most Idaho counties. Net migration accounted for more than 75% of total population growth in 41 of Idaho’s 44 counties. In all, net migration in Idaho was 49,289 from 2020 to 2021, while natural change was just 4,389 – only 8% of the total growth. In many Idaho counties, deaths outnumbered births, resulting in negative natural change. In all, 17 counties had negative natural growth, including all five counties in northern Idaho.
Population growth was similarly distributed among Idaho’s Metropolitan Statistical Areas (MSA). The fastest growing MSA was Coeur d’Alene, which grew by 4.1% to just under 180,000. This was followed closely by the Boise MSA, which grew by 3.3% to 795,000. The remaining four Idaho MSAs grew more slowly, but still experienced net growth, with Idaho Falls MSA at 2.9%, Twin Falls at 2.1%, Pocatello at 1.2% and Lewiston at 0.7%. On aggregate, Idaho’s MSAs grew by 3%, significantly outpacing the growth rate for MSAs nationally, which was only 0.1% from 2020 to 2021. In total, 74.5% of Idaho’s population now lives in the six MSAs.
You can view Idaho county population data for 2020 and 2021 below.
You can find more complete data for Idaho and the nation on the Census website HERE.