Joblessness in August was lower than a year ago in all of Washington state’s 39 counties, according to Employment Security Department data released Tuesday.

King County’s unemployment rate was 5.6 percent last month, up from 5.1 percent in July but down from 6.8 percent in August 2012. Pierce County’s rate declined to 7.7 percent from 8.2 percent in July and 9.1 percent a year ago.

In Snohomish County, joblessness rose six-tenths of a percentage point over the month to 6.2 percent. Still, that was well below its year-ago rate of 7.5 percent.

The county unemployment data are not seasonally adjusted for month-to-month fluctuations and are based on a household survey.

As previously reported, the state’s seasonally adjusted unemployment rate was 7 percent last month, up from 6.9 percent in July.

Amy Martinez: 206-464-2923 or amartinez@seattletimes.com. On Twitter: @amyemartinez