The federal Bureau of Labor Statistics found the county's average weekly wage was $638 in the third quarter of 2013. That was the sixth-lowest among the state's 39 counties.
Kittitas County had the 13th-lowest average wage in the state, $651.
Both Yakima and Kittitas Counties were among the 37 counties with wages below the national average of $922 per week. Only King County and Snohomish County workers earned more.
The lowest weekly wage in the state was $518 in Okanogan County.