Depositphotos LA and San Diego feel the squeeze Southern California is used to growth, so a population dip gets noticed fast. That is why this shift stands out: new Census estimates show both metro areas shrank in the year ending June 2025, breaking a pattern many residents assumed would always hold. The shift did not come from one single cause. It came from fewer newcomers arriving, more residents leaving for other parts of the country, and a slower national growth picture overall. Depositphotos LA and San Diego lost their cushion For years, LA and San Diego could absorb many people moving away because international arrivals helped refill the pipeline. That cushion got much thinner, and the math stopped working the way it once did. That matters because big coastal metros often depend on a steady flow of newcomers to maintain their population. Once that stream slows, long-running domestic losses become much harder to hide. Depositphotos LA and San Diego face a harder equation The biggest change is how quickly the balance flipped. Fewer people are arriving from abroad, just as more residents decide the cost of staying is too high. That makes these losses feel different from a normal reshuffling. Southern California is not just losing residents to cheaper places. It is also receiving less help from international migration, which once softened those departures. Depositphotos LA’s outflow was hard to miss Los Angeles saw one of the clearest examples of the problem. In the year ending June 2025, the Los Angeles metro area lost about 131,000 residents through domestic migration while gaining about 38,500 through international migration, leaving a difficult-to-overcome gap. That gap was far too large to close. Those numbers help explain why the region shrank even though LA still attracts people from around the world. The city’s pull remains strong, but it was not strong enough to offset the number of people who moved elsewhere in the U.S. Little-known fact: Large metros like Los Angeles often depend on international migration to offset domestic outflow when births no longer outpace deaths by much. alfribeiro/Depositphotos San Diego is seeing the same pressure San Diego is following a similar pattern, even if the headlines often focus more on Los Angeles. Census-based reporting showed the San Diego metro area also shrank in the year through June 2025 as domestic outflow outpaced gains from international migration. That is a big deal for a region that usually benefits from weather, universities, military jobs, biotech growth, and cross-border trade and tourism. Those strengths are still there, but they are now colliding with housing costs and a weaker stream of new arrivals. Fun fact: San Diego was one of three top-20 U.S. metros named in reporting as having declined alongside Los Angeles and Miami. Depositphotos Housing costs keep pushing people out A lot of people do not leave Southern California because they stop liking it. They leave because housing, commuting, and everyday bills can make the region feel unmanageable, especially for younger families trying to build a stable life. This is one reason domestic migration has stayed negative. When that pressure builds long enough, even strong job markets cannot fully hold people in place. A cheaper home in another state can become more convincing than another year of stretching every paycheck. MichaelVi/Depositphotos Immigration slowed almost everywhere This is not only a California story. The Census Bureau said nine out of 10 U.S. counties recorded lower net international migration from July 2024 through June 2025 than the year before. That broader pullback matters because large metros depend heavily on newcomers. When immigration slows across the map, places like LA and San Diego feel it quickly because they were already managing domestic losses before the latest decline arrived. leont/Depositphotos Big cities depend on new arrivals Large urban areas usually attract immigrants, younger workers, and early-career residents more than smaller places do. That is why demographers keep pointing to immigration as a key factor in whether major metros grow or slip backwards in a low-birthrate, aging country. Once that inflow weakens, big metros have less margin for error. The losses do not need to be dramatic in every category. They just need to arrive at the same time. That is what makes this moment feel so important. kennytong/Depositphotos Smaller metros are gaining the advantage Coverage of the new Census estimates highlighted fast-growing smaller metros like Ocala and Myrtle Beach, along with places like Wilmington and St. George that kept adding residents even as big coastal hubs slowed. That does not mean every growing metro is cheap or easy. It does mean more Americans are willing to trade prestige and coastal access for lower housing costs, more space, and a better day-to-day financial balance. Elenaferns-photo/Depositphotos This hits more than census charts Population change is not just a numbers story. When metros shrink, it can affect the labor pool, apartment demand, school enrollment, tax planning, and the broader mood around local growth. That is why this trend matters even to people who never look at Census releases. LA and San Diego are still major economic engines, but slower growth can make their challenges harder to solve. A region under cost pressure feels even tighter when fewer new residents replace those who leave. Depositphotos The rebound is not guaranteed Southern California has bounced back from population slowdowns before, so it would be a mistake to treat one year as destiny. Still, the latest figures suggest the old growth formula is under more strain than it has been in years. A rebound would likely need more than one fix. It requires stronger housing affordability, steadier migration flows, and enough economic opportunity to convince more residents that staying is worth the cost. Depositphotos The story is bigger than California What is happening in LA and San Diego also says something broader about the country. Census-based coverage noted that 83 of the nation’s 387 metro areas lost population in the latest estimates year, up from 52 the year before, underscoring how widespread the slowdown has become. That is a noticeable change in momentum. So this is not just a local warning sign. It is part of a national shift in which slower immigration, ageing populations, and migration toward cheaper metros are redrawing the map of growth. It is part of a much bigger shift than one region losing people. See why the immigration crackdown in Minnesota is affecting new home construction timelines. beer5020.gmail.com/Depositphotos Simon is a globe trotter who loves to write about travel. Trying new foods and immersing himself in different cultures is his passion. After visiting 24 countries and 18 states, he knows he has a lot more places to see! Learn more about Simon on Muck Rack.