Seattle, Tacoma Lead as Washington's Population Growth Cools

Washington State’s population growth has slowed significantly, according to April 2026 estimates from the Office of Financial Management. Seattle added 6,800 residents (0.8% growth), while King County grew by 13,000 residents total, reaching 2.4 million. Statewide, net migration dropped 30% year-over-year, though the state added 41,000 housing units, with 62% being multifamily developments.