The Tri-Cities’ explosive growth slowed in 2025, keeping pace with the state’s trend.

Benton County grew 0.81%, or by 1,775 people, and Franklin County grew 0.93%, or by 950 people, according to recent population data estimates from the state Office of Financial Management.

The state’s population also slowed last year, with an unadjusted growth rate of 1%.

As of April 1, 2025, Washington’s total population grew by an estimated 79,400, for a total population of 8,115,100. That growth is slower than the annual average from the last decade which saw 98,200 more people between 2010-20. 

Net migration is the largest driver of population growth in the state, accounting for 78% of growth, or 61,700 people. That’s down 7,500 from last year, making it the lowest level since 2013 except for the pandemic year 2021.

Benton County had a net migration of 893, and Franklin County had a net migration of -14.

At the same time, the statewide birth rate has been declining statewide since 2017 while deaths, both pre- and post-Covid-19 pandemic, have been trending upward.

Housing has continued to grow in the state, with 47,900 housing units added in the past year – 4,300 less than the year before. While Washington’s population growth is still strong, the population pressure driving housing demand is easing as new units are completed.