Seattle, the fastest-growing big U.S. city of the 2010s, isn’t growing so fast anymore.

Newly revised population data from the Washington Office of Financial Management shows the state’s largest city only grew by 0.7% from April 1, 2020 to April 1, 2021 — that’s a net gain of about 5,400 people.

That puts the total population of Seattle at just over 742,000.

It’s a far cry from the population gains we saw through much of the 2010s, when the city sometimes grew by more than 3% in a single year.

It should be noted that the state revised its 2021 population estimates at the end of last year. Initially, the figure for Seattle was quite a bit higher, at nearly 770,000, which made it appear that city’s population had grown at a significantly faster rate.

Why did the state revise its numbers downward?

Their initial estimate came out before we got our first glimpse of the 2020 census data, which was released in August. The 2020 census numbers are, of course, a head count of every person living in the U.S. (or, at least, our the best attempt at a head count). As such, these numbers are the benchmark for all population estimates over the course of the decade.

And the 2020 census showed Seattle’s population was just 737,000. That figure is even lower (by about 10,000) than the state’s 2019 estimate for Seattle.


Does that mean that Seattle’s population shrank in 2020? It’s possible. There were certainly a lot of anecdotes about people leaving big cities during the pandemic, choosing to relocate in the suburbs or smaller towns.

But it’s also possible that our 2019 population estimates were a little inflated, and the 2020 census just represents a correction, rather than a shrinking population in Seattle.

If Seattle did shrink a little in 2020, that doesn’t appear to be a lasting trend. While the city’s 0.7% growth in 2021 is modest, it’s still growth.

And that’s not really a surprise when you look at the housing market in Seattle. The city is still adding housing units (check out all the new high-rises along Denny Way in South Lake Union), the market for homes is red-hot, and rents are up slightly from before the pandemic. These are not signs of a shrinking city.

The state uses a wide variety of records to determine changes in population. Some examples include vital statistics data (births and deaths), a host of administrative records (counts of registered voters, licensed drivers, motor-vehicle registrations, K-12 students, Medicaid and Medicare recipients), housing data (number of completed housing units, postal delivery statistics, etc.) and data from “group quarter” housing (dormitories, nursing homes, prisons, etc.).

Seattle isn’t alone in its slower rate of growth. Bellevue’s population only increased by 0.5% in 2021, a net gain of about 750 people. Bellevue’s population now stands at nearly 153,000. And Tacoma’s population shrank slightly, down 0.3% from 2020, to just under 219,000.


Of the largest cities in our metro area, Everett had the fastest growth, at 1.5%, bringing the population to 112,000. Among cities with at least 30,000 residents, Lake Stevens grew the fastest, at 3.9%.

The fastest growth rate in our metro area — and by a wide margin — was in the small city of Black Diamond, about 30 miles southeast of Seattle. Its population grew by 13% in 2021, an increase of more than 600 people. Black Diamond is home to a large new master-planned community called Ten Trails, which is being built in phases. This community, which opened in 2018, will eventually include roughly 6,000 homes, bringing more than 15,000 people to Black Diamond.

The other fastest-growing places in our metro area last year were, like Black Diamond, small cities not in close proximity to Seattle: Edgewood, Bonney Lake, Sultan and Arlington. All these places grew by more than 4%.

This does seem to support the idea that the pandemic, and the subsequent rise of working from home, is pushing more people toward smaller communities — places where you get more home for your buck, and where there’s easy access to outdoor recreation.