Orange County's jobless rate for May jumped to 3.4% from 2.9% in April to hit its highest level since July, 1987.
But state labor analysts said the increase, which was in line with hikes for the rest of California's counties, was caused by a shift in the method used to generate unemployment statistics rather than by any significant change in the employment situation.
Statewide, the unemployment rate soared to 6.3% from April's 5.1%, and in Los Angeles County the rate was hiked to 5.2% from the previous month's 4.3%.
While the highest its been in 10 months, Orange County's May jobless rate still is considered to be a very low one. Most economists consider any area with an unemployment rate of 5% or less to have full employment.