The Department of Labor and Industries recalculates the state's minimum wage each September as required by Initiative 688, which was approved by Washington voters in 1998. The law requires that the state minimum wage be adjusted each year according to the change in the federal Consumer Price Index for Urban Wage Earners and Clerical Workers during the 12 months ending each Aug. 31.

The index measures the average change in prices for goods and services such as food, shelter, medical care, transportation and other goods and services people purchase for daily living. It increased 3.8 percent during the 12-month period ending Aug. 31, 2005, compared to a 2.6 percent increase during the same period in 2004.

Washington's minimum wage applies to workers in agricultural and nonagricultural jobs, although 14- and 15-year-olds may be paid 85 percent of the adult minimum wage.