California's population declined by nearly 10,000 residents in 2025, marking a 0.02 percent decrease and continuing a trend of outward migration. This makes it one of only five states to lose population year-over-year, according to an analysis of US state population changes.
Despite the dip, California, with a population of 39,355,309, still holds its position as the most populous state in the country. The state's population was recorded at 39,364,774 in 2024.
This recent decline follows a longer pattern of population loss over the past 15 years. Between 2010 and 2024, California saw approximately 10 million residents leave for other states, while just over 7 million moved in. The sharpest period of population loss occurred between 2020 and 2021, when the state's population decreased by a record 374,900 individuals in a single year.
Among the states that experienced population decreases in 2025, Vermont saw the largest percentage loss at approximately 0.3 percent, followed by Hawaii at 0.2 percent. In contrast, South Carolina and North Carolina were among the states with the most significant population growth, with increases of 1.46 percent and 1.32 percent, respectively.
The overall US population growth has slowed dramatically, with the year-over-year increase now below 1 percent. The analysis also highlighted demographic shifts in other states, with Utah identified as the youngest state with a median age of 33, while Northern New England, particularly Maine, has the oldest population, with a median age of 45.
While population decline can strain state resources and services, it can also potentially alleviate pressure on housing and infrastructure, possibly leading to improved affordability for remaining residents. Conversely, population growth can bolster labor availability and expand the consumer base, contributing to economic expansion.