U.S. population growth slowed to levels not seen since the pandemic brought migration to a halt, according to newly released U.S. Census data, which also shows that California has become one of the slowest growing states in the nation.
Between July 2024 and July 2025, the U.S. population grew by just 0.5%, according to the Census estimates – the slowest rate since 2021, when the national growth rate of 0.2% was the lowest on record. That deceleration is largely due to a historic slowdown in international migration, according to the Census Bureau.
The changes, which cover July of 2024 through July of 2025, appear to be an early indicator of how Trump’s immigration policies are impacting the nation’s population. That time period includes Trump’s ramp up in courthouse arrests as well as enforcement surges in Los Angeles, but does not include more recent crackdowns across the country, including those in Chicago and Minneapolis.
It’s a sharp turnaround from 2024, when the country experienced its fastest growth since 2006. That change, in contrast, was fueled by a surge in international migration.
Of the top 20 most populous states, California was the slowest growing, with an estimated loss of about 9,500 people – a number that essentially shows no change in the state’s overall population of 39.4 million. Like the U.S. at large, the decline is the opposite of what California saw last year, when immigration contributed to an increase of more than 200,000 people in the state’s population.
New York also saw a 0% change, though it had an estimated increase of about 1,000 people, also a tiny drop compared to the state’s population of 20 million.
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The Census estimates, which measure from July to July of each year, are a different data set than California’s own Department of Finance estimates, which were released in December and similarly found almost no change in California’s population, and that the slowdown was fueled by a sharp drop in immigration.
The state’s estimates generally do not include undocumented immigrants who are not registered with a government entity like a school system or immigration court. The Census Bureau estimates, on the other hand, attempt to account for both legal and illegal immigration, though it does not distinguish between the two.
Nationally, the Census estimated that the net number of immigrants fell by more than 50% between 2024 and 2025. Agency staff predicted that number will continue to fall into this year, as policy changes under the Trump administration continue to play out.
In California, the estimated change as of July last year was even sharper, with an almost 70% decrease compared to 2024. Still, the overall net number of immigrants in California was only slightly lower than historic numbers over the last decade. California also continued to see an exodus of residents to other states.
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The population decrease could have a large impact on California’s influence in Washington, D.C. Dr. Jonathan Cervas, a political science professor at Carnegie Mellon University, forecast that in 2030 California would lose four congressional seats with the 2025 population estimates, according to The Redistrict Network, which provides information about the redistricting.
This article originally published at California is the U.S.’ slowest-growing large state.