Since the 2010s, Seattle has been on a seemingly unstoppable growth streak — minus a small blip at the start of the pandemic. But according to the latest population estimates released by the Washington office of financial management, the Emerald City's turbocharged engine is finally cooling off. Between April 1, 2025, and April 1, 2026, Seattle added 6,800 new residents, bringing its total population to 823,400. That amounts to a growth rate of around 0.8%.