The U.S. Census Bureau released their county-level vintage 2021 population estimates, and they report that more than 73% (2,297) of U.S. counties experienced natural decrease in 2021 - up from 45.5% in 2019 and 55.5% in 2020. In Colorado, 35 of the 64 counties (55%) experienced natural decrease. Natural decrease occurs when there are more deaths than births in a population over a given period. Aging in the U.S. and Colorado, as well as increased mortality due to COVID and fewer births, contributed to this rise in natural decrease.
Among Colorado's population changes, 60,700 babies were born, 48,000 died, and 15,000 more people moved in than moved out. While there are more women of childbearing age in Colorado since the last census, annual births are at their lowest levels since the late 1990s. Annual deaths were at the highest levels on record due to COVID-19 and aging. The metro counties of Pueblo and Mesa lead the list of counties in natural decrease, though most of the counties in a phase of natural decline were in the non-metro parts of the state and ranged from -560 to -1. Net migration (the difference between the number of persons moving in to Colorado and the number who moved out) was estimated at its lowest levels since the tech bust during 2003-2005. Net migration included 13,400 in net domestic migration and 1,600 in international migration. Twenty of Colorado’s sixty-four counties reported net out-migration led by Denver, Jefferson, Arapahoe, Boulder, and Adams counties. These estimates are subject to revision next year as more data becomes available. The State Demography Office will release vintage 2021 estimates this summer that will be slightly different based on more current birth and death data.
Top Five Largest Growth by County
- Douglas:8,888
- Weld: 8,678
- El Paso: 6,020
- Larimer: 2,847
- Adams: 1,977
Top Five Largest Declines by County
- Denver: (6,167)
- Jefferson: (3,347)
- Boulder: (1,268)
- Arapahoe: (212)
- Rio Grande: (130)
In December, the Census Bureau released national and state-level estimates showing the U.S. population grew at a slower rate in 2021 than in any other year since the founding of the nation. This was based on historical decennial censuses and annual population estimates. The U.S. grew by 392,635 or 0.1%, and Colorado increased by 27,761 or 0.5%. Seventeen states and the District of Columbia lost population, 11 which had losses over 10,000, and three with losses over 100,000. Colorado’s growth ranked 17th in percent change and 11th in total change compared to other states. Colorado has not experienced this slow level of growth since the late 1980s in terms of both total growth and growth rates.