Rush-hour traffic on the Connector in downtown Atlanta.

ATLANTA—Since the invention of air conditioning, Atlanta has known one constant: growth.

The region is finally cooling off.

Census data show more people from within the U.S. left metro Atlanta than moved to it during the 12 months that ended in mid-2024. It was a modest decline, about 1,330 people. But it heralds a significant moment for the longtime growth magnet: This is the first time metro Atlanta lost domestic migrants since the Census Bureau started detailing these numbers three decades ago.

There are other signs the city is losing its edge, including weak hiring among local employers and higher-than-average office vacancies. A 623-unit apartment complex in the city’s Buckhead neighborhood—a building once famous for an electronic sign that counted Atlanta’s expanding population—went into foreclosure last year.

Growth in some other big Sunbelt metros has slowed, too, after pandemic-fueled population surges, including around Phoenix and Tampa, Fla., the census data show. Recent Bank of America change-of-address data also show big metros in the region losing steam.

Surging housing costs and endless traffic are pushing people to choose smaller, cheaper cities instead, and this is starting to shift the balance of power in the southern U.S. These movers still include people who are leaving pricey northern cities, but also include people giving up on large southern metros like Atlanta.

Adelia Fish says she and her husband DeJuan McBurnie moved to Chattanooga, Tenn., from Atlanta for a more affordable lifestyle.

“We just couldn’t afford to live there and have the lifestyle we wanted,” said Adelia Fish, 29 years old, who left suburban Atlanta with her husband in May for a newly built, three-bedroom home in Chattanooga, Tenn.

Fish said the couple, who have IT careers and are expecting their first child this summer, pay less for their new mortgage than they would for rent in their Atlanta-area townhouse.

Losing people is unfamiliar territory in Atlanta. Since 1950, the region’s population has mushroomed almost 10-fold to 6.3 million and sprawled across 29 counties, creating the nation’s eighth-largest metro area. The region averaged a net gain of about 33,000 domestic newcomers in the five years before Covid-19 hit.

Housing and job opportunities kept pulling people in, often from northern cities. Even the city’s beloved baseball team, the Braves, is a 1960s northern migrant by way of Milwaukee and Boston. The call letters for Atlanta radio and television stations WSB have long been used for the slogan “Welcome South, Brother.”

The latest census metro-area estimates, which cover the 12 months ended June 30, 2024, still show a growing Atlanta region overall. That is because births outnumber deaths there, and because of what had been surging international immigration before President Trump took office again.

Atlanta’s housing hasn’t kept pace with population growth.

A home for sale in Smyrna, Ga., a suburb near Atlanta.

But when it comes to domestic migration, Atlanta is losing a long-running source of economic strength. This risks making the area less appealing for companies seeking big pools of skilled workers, said Mark Seeley, who advises companies on corporate relocation for the real-estate brokerage CBRE.

Atlanta’s housing hasn’t kept pace with population growth. In the 1990s and 2000s, the region’s housing stock grew by around 3% a year on average, economists Edward Glaeser and Joseph Gyourko found, based on census data. But that fell to 1.1% in the 2010s and just 0.6% between 2020 and 2023. Other Sunbelt cities like Phoenix, Dallas and Miami also saw drops in home-building.

Even as Atlanta’s apartment construction boomed after the pandemic, single-family home-building remained well below levels seen during growth spurts in prior decades, according to John Burns Research and Consulting. Another concern in the region is that the boom in data centers is starting to compete with housing.

“Here is the challenge that everybody recognizes, we need to build more houses,” said Mike Alexander, chief operating officer for the Atlanta Regional Commission, a local planning agency. He said Atlanta isn’t unique among major metros in experiencing flattening growth.

Luxury apartments for lease in midtown Atlanta.

Atlanta-area home values tripled to about $390,000 since February 2012 while outpacing national growth, Zillow data show. Home values there also exceed the national average.

For Atlanta and other big Sunbelt metros, “their housing supply has increasingly gone the way of coastal America,” said Glaeser, the economist.

The last several years have been a dynamic time for migration in Sunbelt metros. Many including Atlanta saw temporary surges in domestic newcomers during the height of the Covid-19 pandemic, fueled in part by people streaming out of places like northern cities that were hit hard early on.

That boom didn’t last long, and growth has slowed notably in its wake. Tampa, Orlando and Phoenix areas all saw smaller net gains in domestic movers in the 12 months ended June 2024 than they averaged before the pandemic.

Fresher data from the Bank of America Institute showed seven of the eight biggest Sunbelt metros, including Atlanta, posted net losses of domestic movers heading elsewhere in the first quarter this year, compared with the last three months of 2024. Their numbers were based on millions of the bank’s card and account holders.

Whether that big-metro slowdown continues remains to be seen. But census data also indicate many smaller regions in the South—places like Huntsville, Ala., Wilmington, N.C., and Knoxville and Chattanooga in Tennessee—are picking up the slack. Their metros are all running ahead of pre-Covid trends.

They have some advantages, including cheaper housing compared with many big metros. Also, the popularity of remote work may help maintain the flow of people to smaller cities, said William Frey, a demographer at the think tank Brookings Metro.

The appeal goes beyond cost of living.

“Atlanta is exactly an hour away from Atlanta,” said Matt Smith, another Atlanta-to-Chattanooga mover, repeating an adage about commuting struggles in Georgia’s capital. The manufacturing salesman, 47, relocated in March. “It’s almost laughable when they talk about traffic here,” he said of his new city.

A quarter of Atlanta’s office space sits vacant, according to brokerage Cushman & Wakefield. That is well above the national average of 20.8%. In 2023, Microsoft indefinitely halted what had been a planned 90-acre, 15,000-employee campus on Atlanta’s Westside. The area remains an empty field blocked off by fencing.

The Holder family left suburban Smyrna, Ga., for their hometown of Greenville, S.C., after feeling priced out of the Atlanta metro area.

The region also has an overflow of high-end units from developers who bet on well-heeled movers. Across the metro area, 12.2% of apartments are vacant, according to data company CoStar Group, up from 7.5% a decade ago.

That doesn’t mean affordable houses are readily available. Carlee and Austin Holder loved the Atlanta area, but felt priced out while planning a family during the pandemic. They left suburban Smyrna, Ga., for their hometown of Greenville, S.C., where they now have a toddler and another baby on the way.

Back in Atlanta, “we couldn’t afford daycare or to buy a house in a nice neighborhood,” said Carlee Holder, a nurse.

Recent Chattanooga movers Fish and her husband DeJuan McBurnie, 28, got their new house there for $320,000. Both have worked in IT management, though Fish is taking a break to have their baby. She also is trying to develop a stand-up comedy career. Chattanooga has fewer venues than Atlanta, but she said she is finding enough gigs to make her new home work.

“We could actually afford to buy something here,” Fish said.