Washington’s population grew by 158,100 people since the 2020 decennial census April 1, 2020, largely due to migration. This means Washington grew to an estimated 7,864,400 people as of April 1, according to annual estimates that the Office of Financial Management prepared.
The state’s total population change was 97,400 since last year, which fell just below the last decade average of 98,200 per year. King County is the main contributor of that growth, adding 30,700 people this year, compared to an average of 33,800 people per year between 2010 and 2020.