The state in February posted its biggest monthly job gains in more than a year, as the unemployment rate slipped to its lowest level since May 2009, the state Executive Office of Labor and Workforce Development reported today.

Massachusetts employers added more than 15,000 jobs last month -- the most since January 2010. The state unemployment rate fell to 8.2 percent, from 8.3 percent in January and 8.8 percent a year ago, the state reported. The national average was 8.9 percent in February, down from 9 percent the previous month and 9.7 percent a year earlier.

"This is consistent with what we're seeing nationally, a sort of recovery that is gaining strength, although we have to wait and see what the fallout from Japan and the Middle East will be," said Northeastern University economics professor Alan Clayton-Matthews. "I'd characterize this as good news."

February's job gains were broad, stretching across several sectors. The largest gains were in education and health services sectors, which added 6,500 jobs. Leisure and hospitality, which include restaurants and hotels, gained 4,300 jobs. Professional, scientific and business services, which include a variety of technology, scientific and consulting firms, gained 2,800 jobs.

The state's financial services sector added 1,100 jobs. Those numbers do not take into account this week's announcement by financial services giant Fidelity Investments to shutter its offices in Marlborough and move 1,100 jobs out of state.

Only three employment sectors lost jobs: Manufacturing shed 1,100 jobs; construction 1,000 jobs; and government 700 jobs.

Andre Mayer, senior vice president of communications and research at Associated Industries of Massachusetts, the state's largest employer group, called the numbers a "very positive sign," but urged caution in interpreting them. The instability of the US economy in recent years, combined with unrest in the Middle East and natural and nuclear disasters in Japan, could affect business and consumer confidence, which are viewed by economists as important to driving the recovery forward.

In general, economists say, don't give too much weight to one month's data, which are frequently revised. Just recently, for example, the state and US Labor Department issued significantly revised job and unemployment figures for the past few years that showed the recent recession in Massachusetts was milder than first thought and the state's recovery weaker.

"We are seeing gains and we are seeing some progress, things are getting better and in some cases people are finding jobs," Mayer said. "But we are not really getting to a stable place of sustained growth. And we have not been able to get past the sense of uncertainty."

The Associated Industries of Massachusetts Business Confidence Index dropped slightly last month, Mayer said, but it remained higher than the same period during the last two years.