Georgia’s unemployment rate jumped to 8.1 percent in August from a revised 7.7 percent in July — even as the number of jobs increased and layoffs declined, the state labor department said Thursday.

The labor department and many economists had been expecting the jobless rate to fall after it had risen in recent months, partly due to seasonal layoffs in schools that began operating again in August. In fact, the rate fell from July to August during the previous two years.

State Labor Commissioner Mark Butler called August’s rate increase “somewhat questionable” in a statement releasing the numbers.

“With continued job growth and fewer layoffs, we would expect the rate to come down,” Butler said in the statement. “We’ve talked with the U.S. Department of Labor’s Bureau of Labor Statistics, which conducts the monthly household survey that determines the national and state unemployment rates,” Butler continued. “They say the ‘volatility’ in the monthly survey numbers ‘is expected’ and that it’s often ‘smoothed’ during the annual benchmarking process. Last year’s initial August rate was eventually reduced by a half-point, and we expect a similar reduction this year.”

The “benchmarking process” Butler referred to takes place at the start of each new year, which is when the unemployment numbers are often revised for the previous year.

Still, it is unusual for a labor commissioner to question the numbers that his own department puts out every month.

Butler, a Republican, did not question the numbers when they were improving.

The latest data will almost certainly be used by Democrat Jason Carter, the candidate challenging incumbent Gov. Nathan Deal in November, to criticize the administration’s job creation record.

In July, Georgia had the second highest unemployment rate in the nation, next to Mississippi. The August ranking of the states is scheduled to be released Friday.

With the U.S. jobless rate for August at 6.1 percent, Georgia now trails the nation by a full two percentage points.

In August, 24,700 new jobs were created in Georgia. There total number of jobs — 4,132,900 — was the most since June 2008.

The monthly gains came in government as 16,600 seasonal school workers returned to their jobs after summer layoffs. Education and health services added 7,700 jobs, manufacturing recorded 4,000 new jobs, construction added 1,600 jobs, and other services added 1,500.

Over the past year, 79,300 more jobs were created. But the unemployment rate has only fallen from 8.2 percent.

Also, initial claims for unemployment benefits — a leading indicator for new layoffs — decreased 27 percent in August to total 31,122. Most of the August decline came in manufacturing, administrative and support services, health care and social assistance, and trade.