While the state's unemployment rate inched up to 9.3 percent last month, the Tri-Cities' rate fell to 6 percent.
Dean Schau, regional labor economist, said the Tri-Cities' unemployment rate, which was down from 6.5 percent in August, was the lowest of all major metropolitan areas in Washington.
While the state has lost tens of thousands of jobs in the past year, Schau said the Tri-Cities has added about 3,000.
The state's job pool has shrunk by 131,200 from a year earlier, a decrease of 4.4 percent. For the same period, the Tri-Cities' job pool has grown 3.1 percent.
Although the Tri-Cities has added about 3,000 jobs in the past year, the number of unemployed workers grew from 5,620 in September 2008 to 7,890 last month.
Schau attributed that growth to the "refuge unemployed."
"I think people are coming in, a lot of them from Oregon, and are looking for work," he said. "Maybe they do find work, but maybe it takes 16 to 20 weeks."
Total nonfarm employment in the Tri-Cities fell seasonally by about 300 jobs from August to September. Much of the job losses were in the leisure and hospitality industries. Nearly 100 construction jobs were lost between August and September as well.
Much of the area's job growth came in agriculture, where farm employment swelled from 11,600 jobs in August to 13,400 jobs in September. "Agriculture looked nice because of the potato harvest," Schau said.
In a separate report this week, chief state economist Arun Raha noted Washington's unemployment rate has remained relatively flat since reaching 9.1 percent in March, the end of the recession's free-fall period.