OLYMPIA, Wash. (AP) -- Washington state's minimum wage will likely not increase for the second year in a row, based on federal inflation numbers released Friday.

The state's minimum wage is tied to inflation, as dictated by a 1998 voter-approved initiative. Inflation, as measured by the Consumer Price Index, fell last year for the first time since the initiative took effect.

Preliminary federal numbers released Friday show an overall increase in the index, though it's still lower than the last time the state minimum wage increased in 2009.

The state Department of Labor and Industries asked Attorney General Rob McKenna if the state would be able to increase the minimum wage if inflation increases, but not above the level the current rate is based upon. In an opinion issued Wednesday, McKenna said no.

L&I spokeswoman Elaine Fischer said Thursday that the state is not making an official determination on the minimum wage until Sept. 30, when the federal government releases its final numbers.

Washington state's minimum wage is $8.55, the highest in the nation. The federal minimum wage is $7.25. Last year was the first year that the state wage didn't go up since Initiative 688 passed, because inflation fell. It's now growing again, but at a slower rate.

"It's an unusual situation that's never occurred before," L&I spokeswoman Elaine Fischer said.

Colorado's minimum wage dropped slightly this year, from $7.28 to the federal level of $7.25, because of the drop in inflation.

Other states with adjustable minimum wages are Arizona, Florida, Missouri, Montana, Nevada, Ohio, Oregon, Vermont and Washington. Most states that tie the wage to inflation make no provision for lowering the amount, including Washington, so the minimum wage stays flat if the cost of living falls.

Copyright 2010 The AP.