D. Patrick Jones: Recent estimates show strong gain for Spokane County

Among the five largest counties in Washington, Spokane took home silver in the population growth sweepstakes last year. Gold went to King County, showing an estimated 1.4% increase from 2024. Spokane County sported a growth rate of 1.2% year-over-year. Not a big gap in percentage terms. Given the much greater population base in King than Spokane County, the resulting gains in head count are vastly different. Spokane yielded an estimated addition of 7,400 new residents. King County chalked up an extra 33,500. Seattle accounted for more than half of that gain.

The three other large counties – all more populous than Spokane – were estimated to have grown less than 1%.

What was behind Spokane County’s growth? Largely, more people moving in, on a net basis, than the natural increase. The latter factor is simply the surplus of births over deaths. While positive, the natural increase was small here: about 1,350. People moving to the county accounted for the bulk, about 6,050. In-migration has weighed much more heavily than the natural increase in the county’s population for years. With declining birth rates in nearly every corner of the country, this relative contribution is not unique.

For the first time in a while, Spokane County’s population expanded more quickly than that of the Tri-Cities. The 2025 year-over-year rate in Benton County was 0.8% while that of Franklin County was 0.9%. The same growth rate characterized the other fast-growing county in Eastern Washington, Grant County.

On a five-year cumulative basis, however, Spokane County’s population hardly takes silver. Between 2020 and 2025, the county gained almost 27,000, or nearly 5%. That rate, however, lay still below the rate in the state’s other large counties, except for Pierce (Tacoma). The winner in this circle was actually Clark County (Vancouver), with a cumulative growth rate of nearly 8% over the first half of the decade.

Further, over the first half of the decade, Spokane County’s population growth was considerably below that of nearly all metro counties of Eastern Washington. The exceptions were Chelan (Wenatchee) and Yakima.

Of course, not all parts of Spokane have grown equally. The 2025 year-over-year results show that most of the fastest-growing towns were on the periphery. Ranked, they were: Rockford (!), Liberty Lake, Medical Lake tied with Spokane Valley, and Deer Park tied with the city of Spokane. The ranking for the cumulative growth rate over the first half of the decade was slightly different: Rockford, Liberty Lake, Deer Park, Spokane Valley and Airway Heights.

How will population growth in the second half of the decade play out? The most recent public forecast available, from the demographers at the Washington Office of Financial Management, was published in November 2022. They forecast a gain from 2025 to 2030 of approximately 24,000, with total population reaching a bit more than 587,000. OFM’s 2022 forecast, however, slightly undershot the actual 2025 estimate. Assuming that the same (small) error holds, the county’s population will likely be about 590,000.

It is hard to imagine that the trajectory of growth within the county will be substantially different in 2030 than it is now. Due to a variety of factors, the periphery should continue to gain at the expense of the city of Spokane. That said, the center of the county’s population gravity, the city of Spokane, will continue to add residents.

D. Patrick Jones is executive director of Eastern Washington University’s Institute for Public Policy and Economic Analysis in Spokane.