The U.S. Census released new population estimates for California counties last week. While most of the Bay Area continues its steady population expansion—albeit at a slower rate than in other recent years—both Sonoma and Napa Counties saw head counts reduced after the deadly 2017 wildfires.
The census figures (which are estimates) cover the period between July 2017 and July 2018. Since the last full census in 2010, North Bay counties have seen population growth almost every year.
But between mid-2017 and 2018, Sonoma County—hit hardest during the 2017 firestorm with disasters like the Tubbs Fire, which Cal Fire records as the second most destructive wildfire recorded in state history—saw its population drop from 503,246 to 499,942.
In Napa County, which is less populated and was the site of fewer of the fires, the decline was less pronounced but still drastic, from 140,386 down to 139,417.
For perspective, Sonoma County has seen average growth of more than 2,700 persons every year since 2010, and Napa grew by more than 500 in an average year.
The census numbers comes with two caveats, first being that these figures are initial estimates and the census will later adjust them for accuracy once more data is completed.
The second thing worth noting is that past years’ population estimates reveal that both counties were already declining in population, albeit it only slightly; between 2016 and 2017, Napa County dropped 799 persons. During the same timeframe, Sonoma County shrank as well, but only by three people.
Marin County is also down over several years, dwindling from 261,016 in 2015 to 259,666 in 2018.
According to the same new census figures, San Francisco grew by 4,139 persons between 2017 and 2018, up to an estimated population of 883,305, one of the smallest spikes in years. The city’s average since 2010 is more than 10,500 annually.
It briefly appeared that SF’s population might actually have dropped, as census figures from the same time last year marked SF’s population as over 884,000.
However, a spokesperson for the US Census Department told Curbed SF those numbers were preliminary, and the census later adjusted them significantly downward for 2017.
The Bay Area population swelled by 21,000 across all nine counties, which, again, is significant but also a much smaller rate of growth than the region has seen as of late.
“Bay Area population growth has been slowing markedly in the past two years, after the extremely high rates of growth for the six previous years,” says Compass real estate economist Patrick Carlisle.
Carlisle also notes that “the fact that the census revised their previous annual estimates to this degree means they may revise their 2018 figures significantly as well,” meaning that growth may end up looking even smaller in the long run than right now, and declines in the North Bay may turn out to be more severe.