The hourly increase of 13 cents, from $9.19 to $9.32 an hour, reflects a change in the Consumer Price Index, according to the state Department of Labor and Industries.
Voters approved an initiative in 1998 that requires the state agency to make a cost-of-living adjustment to its minimum wage each year based on the federal Consumer Price Index for urban wage earners and clerical workers.
Washington has the highest minimum wage in the nation, followed by Oregon. The minimum wage in Oregon is also set to go up Wednesday, by 15 cents, from $8.95 to $9.10. The federal minimum wage is $7.25 an hour.
Washington has become a flash point in a national debate over raising the minimum wage. Seattle Mayor-elect Ed Murray has said he would give a task force of business, labor, government and academics four months to come up with a plan to raise the city's minimum wage.
Meanwhile, voters in the city of SeaTac narrowly approved a $15 an hour minimum wage in the November election, but a judge last week struck down the measure as it applied to the vast majority of workers.
King County Superior Court Judge Andrea Darvas ruled the city initiative applies to about 1,600 hotel and parking lot workers in the city but that the measure does not have authority over 4,700 employees and contractors working within Seattle-Tacoma International Airport, which is operated by the Port of Seattle.
Supporters of the measure filed a petition Tuesday with the state Supreme Court seeking a review of the judge's decision.
Alaska Air Group Inc. and other businesses are leading the challenge against the newly approved measure.
Washington's minimum wage has gone up every year since 1999, according to state labor data.
The state is one of 10 that adjust the minimum wage based on inflation and the Consumer Price Index, labor officials said. The others are Arizona, Colorado, Florida, Missouri, Montana, Nevada, Ohio, Oregon and Vermont.
The state's minimum wage applies to workers in both agricultural and nonagricultural jobs, although 14- and 15-year-olds may be paid 85 percent of the adult minimum wage, or $7.92 per hour in 2014.