The Tri-Cities posted its lowest unemployment rate of the year in September, 5.9 percent, up from 5.5 percent a year ago.

The state’s seasonally adjusted unemployment rate fell to 5.6 percent in September with the state adding 20,000 jobs, according to preliminary estimates from the federal Bureau of Labor Statistics.

The state’s unemployment rate was 5.7 percent in August, after lingering for eight months at 5.8 percent.

The Tri-Cities’ labor force grew to 134,872 in September, an increase of 467 from the previous month. The area’s labor force grew by 4,581 year over year.

The labor force is the total number of people in the workforce, both employed and unemployed, over age 16.

The state’s private sector added 14,300 jobs and the public sector gained 5,700 jobs, according to the Washington’s Employment Security Department.

“Bigger picture, Washington is continuing to add jobs,” said Paul Turek, the state’s labor market economist, in a statement. “We’re seeing growth in the labor force while trimming unemployment as employers continue to pull people back off the sidelines and into the job market.”

The national unemployment rate increased to 5 percent in September. The unemployment rate in the Seattle/Bellevue/Everett area dropped from 4.1 percent in August to 3.9 percent in September.

The Tri-Cities’ greatest job growth occurred in government with 800 new jobs between August and September. Signaling the end of summer, the leisure and hospitality sector lost 200 jobs.

Year over year, 12 of 13 of the state’s major industry sectors added jobs. Manufacturing was the only sector to report job losses with 4,000.

The state’s three industry sectors with the largest employment gains year-over-year, not seasonally adjusted, were education and health services with 21,100 new jobs; construction with 16,000 new jobs; and professional and business services with 13,400 new jobs.