The December figure is up one-tenth of a percentage point from 8.5 percent in November. The rate was 9.4 percent in December a year ago.
State Labor Commissioner Mark Butler said a combination of factors led to the increase. They include what he called a modest increase in new layoffs, along with a small job loss driven primarily by seasonal layoffs in education.
Despite the increase, Butler said it was the best November-to-December job market report since 2007.