The increase translates to $310 a year for the average affected worker. The minimum wage will rise in nine other states, including Northwest neighbors Oregon and Montana. The minimum wage in British Columbia went up last spring to $10.25 (Canadian) an hour.
The hike in low-income wages results from a 1998 ballot initiative, championed by organized labor and opposed by some business groups, that provides annual rate adjustments to keep pace with the rising cost of living.
"Washington's modest annual minimum wage increases have proven incredibly valuable in promoting economic growth and protecting the real value of low-wage workers' paychecks during the weak post-recession recovery," said John Burbank, director of the Economic Opportunity Institute.
"Congress should learn from Washington's example and pass a federal minimum wage increase with annual cost-of-living advances to promote consumer spending and help cash-strapped workers make ends meet," Burbank added.
The federal minimum wage stands at $7.25 an hour.
Congress last voted to increase it in 2007, with the federal minimum wage ramping up to its present level on July 24, 2009.
In 1996, back when bipartisan cooperation was still possible in Washington, D.C., President Clinton worked out a deal with House Speaker Newt Gingrich and a Republican-led House to increase the minimum wage. Such deals have become rare 16 years later.