The “most millennial city” claim hit San Francisco, but does the data back it up?

San Francisco County millennial share in 2024

The City and County of San Francisco, California, stands out as one of the most millennial-dense large counties in 2024, based on U.S. Census data analyzed by the San Francisco Chronicle.

About 27% of residents were ages 30 to 44 in 2024, used as a stand-in for millennials born between 1981 and 1995.

That 27% share is the highest for any 15-year age group in San Francisco County. Among U.S. counties with more than 500,000 residents, San Francisco ranks fourth in the share of people ages 30 to 44.

San Francisco County is California’s top 10 entry

San Francisco County was the only California county in the national top 10 for millennial share among counties with populations over 500,000, using 2024 U.S. Census data. The article places San Francisco County fourth on that list.

Los Angeles County and Sacramento County were cited as large California counties that did not appear in the top 10 ranking. Alameda County was cited as the only other California county in the top 20.

San Francisco County matches other tech hubs

San Francisco County appears alongside several other large counties in the millennial share ranking. The article groups San Francisco County with Denver County, Washington, D.C., and Hudson County, which includes Jersey City and Hoboken.

Close behind in the same discussion are Travis County, Multnomah County, and King County.

The article says these areas have been liberal or countercultural and later became tech job centers. The millennial measure used in the ranking is the 2024 share of residents ages 30 to 44.

San Francisco County stayed near 30% over time

San Francisco County has kept a high millennial share over the past decade. In 2014, residents ages 20 to 34, the millennial approximation for that year, made up about 29% of the population, according to the Chronicle’s Census analysis.

In 2024, San Francisco County residents ages 30 to 44 made up 27%, using a new age band as the generation aged. The article says the share decreased by less than 2 percentage points over the 10 years.

The comparison treats ages 20 to 34 in 2014 and ages 30 to 44 in 2024 as the closest millennial approximations in the available data.

San Francisco County led the 30 to 44 share

San Francisco County had a 27% share of residents ages 30 to 44 in 2024, the largest share of any 15-year age group in the county, according to U.S. Census data.

A decade earlier, San Francisco already had the highest share of 30- to 44-year-olds among large counties, at 27%, the same share it holds in 2024.

San Francisco County shows fewer under 30

San Francisco County saw a notable shift in the decade comparison cited in the article between younger and older residents. San Francisco and Washington, D.C. each had a three-percentage-point drop in the share of residents in their late teens and twenties.

The article says the share of residents in their 30s and early 40s increased nearly everywhere. San Francisco was described as an aging place in the same discussion.

San Francisco County differs from key peers

Denver County showed little change in millennial share across the last ten years, according to the article’s comparison of county age shares. The article says Denver saw almost no change in the share of residents in that generation over the decade.

Washington, D.C., moved in the opposite direction. The article says Washington, D.C., saw the millennial share drop by more than 3 percentage points over the last 10 years.

San Francisco County uses an age band proxy

The article defines Millennials as people born from 1981 through 1995. The U.S. Census tables cited did not list generations, so the article used ages 30 to 44 as the closest approximation in 2024.

Using that proxy, 27% of San Francisco County residents were ages 30 to 44 in 2024. The article says the 27% share was the largest for any 15-year age group in the county.

San Francisco County contrasts with Gen Z share

San Francisco County had a large millennial share in 2024, while the article notes fewer 20-something Gen Z residents. The article ties that statement to U.S. Census age shares.

In 2024, 27% of San Francisco County residents were ages 30 to 44, used as the closest millennial approximation. That 27% was the largest share for any 15-year-old age group in the county.

San Francisco County is not the only example

The article says the millennial share pattern is not unique to San Francisco County, despite its fourth-place ranking among large counties. Many other large counties also had many residents aged 30 to 44 in both 2014 and 2024.

San Francisco County had a 27% share of ages 30 to 44 in 2014 and the same 27% share in 2024, using U.S. Census data cited in the article. That stability is presented as a key feature.

San Francisco County’s ranking depends on the size rules

San Francisco County ranked fourth among U.S. counties with populations over 500,000 for the 2024 share of residents ages 30 to 44, using U.S. Census data cited in the article.

The article says 27% of San Francisco County residents were ages 30 to 44 in 2024. The article says the 27% share was the largest for any 15-year age group in the county.

The article notes San Francisco County was the only California county in the top 10. Alameda County was cited as the only other California county in the top 20. Los Angeles County and Sacramento County were outside.

San Francisco County change centers on young adults

San Francisco County retained 30- and 40-somethings more than younger adults, according to the article’s decade-by-decade comparison. The article says San Francisco and Washington, D.C., showed the most significant shifts.

The article reports a three percentage point drop in the share of residents in their late teens and twenties in both San Francisco and Washington, D.C. The article says the share of residents in their 30s and early 40s increased nearly everywhere.

To see how the city is trying to rebuild momentum beyond tech demographics, check out San Francisco, which experienced a positive shift in tourism trends in 2025.

San Francisco County fits a broader county pattern

San Francisco County shares traits with other millennial-heavy counties listed in the article’s comparison. The article says these counties have historically been liberal or countercultural and later transitioned into tech job centers.

The peer counties named include Denver County, Washington, D.C., and Hudson County, New Jersey, which includes Jersey City and Hoboken. Those examples show the pattern extends beyond California.

For a broader snapshot of where millennials are quietly moving next, check out the places across the US seeing a quiet wave of millennial newcomers.

What do you think about the “most millennial city” label for San Francisco? Does the data back it up? Please share your thoughts and drop a comment.

This slideshow was made with AI assistance and human editing.

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