San Luis Obispo County's jobless rate was 4.1 percent in September, down from 5.4 percent in September 2014 and below August’s revised 4.7 percent rate.
The California Employment Development Department releases monthly data on employment and industry rates.
The county's rate last month also was below the unadjusted September unemployment rates of 5.5 percent for California and 4.9 percent for the nation.
Because of seasonal work fluctuations — which can be significant — unemployment data are compared with the same month year over year.
September's rate was eighth best among the state's 58 counties. San Mateo County reported the lowest September jobless rate in the state, at 3 percent. Imperial County reported the highest, at 21.6 percent.
Last month, 134,800 people were counted as employed in San Luis Obispo County out of a total civilian labor force of 140,500. The labor force includes everyone working and looking for work.
Excluding the self-employed, companies and agencies in the county reported 3,700 more jobs in September than in the same month last year — a 3.4 percent increase.
Gains in the mining, logging and construction industries boosted job growth in the county, with 1,000 total jobs added in September — a 15.4 percent increase year over year.
Gains in the educational and health services industries also led employment in the county in September, with 900 jobs added — up 6.2 percent from the same month last year.
The professional and business services industries lost a net total of 300 jobs in September, down 2.5 percent from September 2014.
Of the largest cities in the county, Atascadero reported the lowest jobless rate last month at 3.4 percent, with 500 out of its 14,600 residents eligible for the workforce counted as unemployed, according to subcounty data from the state Employment Development Department.
The city of San Luis Obispo's jobless rate was 4.3 percent in September, with 1,100 of its 24,500 eligible residents counted as unemployed.
Paso Robles reported a rate of 4.6 percent, with 700 of its 15,300 eligible workers unemployed.
Arroyo Grande reported a rate of 3.5 percent, with 300 of its 9,100 eligible workers unemployed.
Data may not add up because of rounding. All unemployment rates reported are calculated on unrounded data.
Because of a smaller workforce at the city level, subcounty rates are subject to large month-to-month fluctuations.