New data released by the U.S. Census shows California’s population went down slightly since 2020.

The data shows that between April 1, 2020 and July 1, 2025, the state’s population stood at 39.5 million people. In 2025, that number dropped by 0.44% to 39.3 million people. The numbers also show that between 2024 and 2025, the population decreased by .02%, from 39.36 million people to 39.35 million.

Residents have left California for more affordable parts of the country over the last 20 years, but a demographer said research by the nonpartisan Public Policy Institute of California shows the issue has been more that the Golden State is experiencing negative population growth.

“We’ve had some negative population growth years for the first time in the state’s history around COVID,” Eric McGhee, policy director and senior fellow at the Public Policy Institute of California, told The Center Square on Wednesday. “That was a new concept. The growth in the population has slowed quite a bit and has also made the state lag other states in terms of its growth, and it’s falling behind states like Texas or Florida.”

Many residents left California for other states, but it has mostly been backfilled by immigrants, McGhee said.

For that reason, losing people to other states hasn’t always meant a decline in the state’s population, McGhee added.

“The out-migration accelerated quite a bit during the pandemic, and immigration slowed to a crawl,” McGhee told The Center Square.

According to the U.S. Census, other states saw more dramatic population decreases over the period spanning from 2020 to 2025. Hawaii saw a 1.26% drop in its population, from 1.45 million to 1.43 million, and West Virginia saw a 1.42% decrease in the same period, from 1.79 million people to 1.76 million.

Some states saw population increases, the U.S. Census data show. Idaho saw a 9.7% increase in its population, up from 1.84 million in 2020 to 2.02 million in 2025. Florida saw an 8.6% increase in its population, up from 21.5 million people in 2020 to 23.4 million in 2025. South Carolina similarly saw an 8.54% increase in its population, putting The Palmetto State at a population of 5.57 million people in 2025, up from 5.13 million in 2020.

Overall, the South saw the biggest population increase by far. Southern states experienced a 5.82% population increase between 2020 and 2025, while Western states saw a 1.85% increase in population. The Midwest saw a 1.14% increase, and the population of the Northeast increased by 1.06%, according to the U.S. Census.

“Probably the biggest thing that’s been going on in recent years is the cost of living,” McGhee told The Center Square. “It’s about paying for housing, in particular. We saw a big increase in the number of people who say housing is the motivator for their move, and that’s no surprise given the really high cost of housing in California relative to other states.”

Historical reasons for why people move, like getting a new job out of state, or moving to be closer to family or friends are still reasons people leave California, McGhee told The Center Square. However, political considerations can also a motivator, McGhee added.

“If once someone is kind of close to deciding if they want to move or not, being a Republican kind of pushes them over the edge more often than being a Democrat does,” McGhee added. “So they’re more likely to move. That’s not likely that that’s a main driver. It’s just sort of an intervening factor that ends up making the political balance of people moving out of the state lean Republican relative to Democratic.”

Demographers at the California Department of Finance did not respond to The Center Square on Wednesday. Officials from the Washington, D.C.-based National Taxpayers Union also did not return calls and emails from The Center Square.