The Bay Area isn’t getting any younger.

In fact, new data released by the U.S. Census Bureau shows that the region’s population of seniors is growing fast. Meanwhile, the Bay Area’s youth and middle-aged population is stagnant and even declining in some counties.

That’s nerve-wracking for economic development boosters, educators and advocates for Bay Area elders. While the region struggles to attract and keep younger people who may no longer be able to pay the bills or buy a home in some of the nation’s most-expensive housing markets, seniors have tended to stay in the Bay Area since the COVID-19 pandemic.

That’s in part because of the region’s famously temperate weather, but also because seniors tend to have deep roots and would have trouble moving if they’re isolated or medically fragile, according to interviews with aging experts.

Even so, many seniors aren’t immune from the high cost of living.

“You could write a very bleak story about this, and it’s not the type of thing that can turn around overnight,” said Jeff Bellisario, executive director of the Bay Area Council Economic Institute. “It does cut to the very heart of what this place looks like 10, 20 years from now.”

In Marin, Napa and Sonoma counties, as well as San Francisco, seniors outnumber children under 18 years old. Elsewhere, the census data shows big gains by seniors since the worst of the pandemic in 2020.

Marin County’s population of residents 65 and older increased 9.3% between April 1, 2020, and July 1, 2024, according to the census data. The 18-to-24 population increased 11.7% over that period, but all other age groups declined.

According to the data, 25% of Marin residents are 65 and up; 28.7% are 45 to 64; 20% are 25 to 44; 7.6% are 18 to 24; and 18.7% are younger than 18.

Kaushik Roy, the chief executive officer of Vivalon, the Marin nonprofit that serves elderly and disabled residents, said the census figures highlight the need to provide seniors with a sense of social connection.

“The latest census data affirms what we’ve long known: Marin’s population is aging rapidly, and the implications are real,” Roy said. “We will continue to see rising challenges for older adults in our community, including social isolation, food insecurity, limited affordable housing and the need for affordable medical care and specialized transportation. I have no doubt that as a community, we will continue to meet these challenges to support our older residents.”

Kristi Denton Cohen, a Mill Valley resident who is chair of the Marin Commission on Aging, said nearly 40% of Marin’s population will be older than 60 by 2040.

“With threatened cuts on services for them … not just the very low income, but others who may have been considered middle income for most of their lives and now are threatened because of fixed incomes and increased costs of living (food, medical, housing) on so many fronts, their presumed financial security is slipping away,” she said in an email. “Ageism and denial about aging by many of us doesn’t help.”

In Alameda County, the senior population grew nearly 14% from July 2020 to July 2024, the census data shows. Meanwhile, every other age group saw negative growth. Population loss was most pronounced for children under 5, which declined nearly 11%.

In Santa Clara County, the senior population grew about 13%. Unlike its neighbor to the north, that county also saw growth in 18- to 24-year-olds — about 8% — and almost 1% growth in adults age 25 to 44. But children are also becoming less common in Santa Clara County. While the senior population grew, children under 5 declined about 14%.

The rising population of seniors was significant enough to buoy the Bay Area’s overall population, which dipped during the pandemic. That age group was the only one with more residents in July 2024 than on April 1, 2020, census data show.

Bellisario said the trend of an aging region appears here to stay: a “glacial wave of demographic change,” he said.

But the aging population isn’t unique to the Bay Area. By 2050, the number of Americans age 65 and up is likely to increase from about 58 million to 82 million, a whopping 47% spike, the census bureau projected in 2023.

Paula Wolfson, a licensed clinical social worker at Avenidas Social Work Services in San Mateo and Santa Clara counties, said the aging trend in the Bay Area is a simple combination of “longevity and economics.” On one hand, baby boomers are becoming seniors, and advances in medicine are helping them live longer.

“There are more people alive at 65 now than ever in the history of humanity,” Wolfson said.

On the other hand, seniors tend to be rooted in their communities, with their neighbors and family nearby, she said. Older residents are more likely than younger Californians to own their own homes. Younger families are leaving the area because it’s expensive, and the job market can be tough if you’re not tech savvy, she said. That’s not enough to push out seniors, Wolfson said.

“They’re settled here,” she said. “They love it here, and they don’t want to leave.”

But aging presents plenty of challenges. Wolfson runs caregiver support groups for families with seniors and supports elders directly. She met recently with Phyllis Wedvick, a Palo Alto resident in her 70s. Wedvick’s husband died just two months ago, and she sought out an Avenidas senior center for emotional support — as well as for the center’s café, where she feels like she’s not alone. She also takes a tech literacy class with other people her age, where she learns about computers and iPhones.

“If I didn’t have this, I’d be calling friends,” Wedvick said. “But I’d be on my own living with a lot of grief.”

On top of that, Wedvick said the death of her husband left her with a very low income. She’s now tasked with finding work, she said.

In the Bay Area, the aging population is straining educational systems. Colleges including Sonoma State University have faced steep budget deficits in part because fewer students are enrolling. In the South Bay, schools are shuttering because families are fleeing the high cost of living. School funding is largely doled out on a per-pupil basis.

And the aging trend bodes ill for economic development, said Bellisario. It means that comparably fewer adults are contributing to economic growth.

One “bright spot,” Bellisario said, is that the health care industry is growing in the Bay Area. That might in part be because seniors are driving demand for primary care, pharmaceuticals and disease prevention, he said.

Jenay Cottrell, director of Marin County Aging and Adult Services, said the agency offers help and information at 415-473-4636, a line that is staffed from 9 a.m. to 4 p.m. weekdays. The staff also fields emails at 473Info@MarinCounty.gov.

“One of the most important things older adults, persons with disabilities and their families should know is where to go in their community to find out about available services and resources, many of which are free of charge and are for people of all income levels,” Cottrell said.

The Independent Journal contributed to this report.