The construction industry has had its ups and downs throughout 2010, and the months of September and October saw the industry’s fortunes rising.

The Associated General Contractors of America found that construction employment expanded in 29 states between September and October. However, the AGC is still cautious about the industry.

“Considering that most states adding construction jobs in October had shed workers in September, it is safe to say that construction employment remains volatile,” said Ken Simonson, the association’s chief economist. “Construction is no longer in free fall, but the industry remains fragile as improvements vary greatly by state and project type.”

Arizona experienced the largest one-month seasonally adjusted percentage increase, 4.4 percent, and Texas the largest one-month total increase in construction employment, 2.3 percent, between September and October. Other states adding large numbers of construction jobs during October included Illinois, Washington, South Carolina and Colorado.

Simonson said that 20 states plus Washington, D.C., lost construction jobs during the past months, while construction employment remained unchanged in Rhode Island. Minnesota lost 2.7 percent of its construction jobs, the highest percent for the month, while Florida lost the most jobs - 8,600 on a numeric basis. Among other states losing construction jobs between September and October were Pennsylvania, Maryland, Georgia and Massachusetts.

Eleven states and Washington, D.C., added construction jobs for the year. The largest year-over-year percentage increase was in Kansas, where construction employment rose 9 percent, followed by Oklahoma; Arkansas; Washington, D.C.; and West Virginia.

Among the 39 states that lost construction jobs over the past 12 months, Nevada experienced the largest percentage decline, down 19.5 percent, while California lost the most jobs, approximately 45,700. Other states experiencing large declines for the year include Idaho, Vermont, Montana and Missouri.

Association officials said that temporary stimulus funding has helped the industry, but that most firms were worried about business levels for next year. They added that private, state and local demand for construction remains weak, while long-term federal infrastructure programs and tax rates remain in limbo.

“We won’t see sustained job growth until the private sector picks up and long-term federal plans are clear,” said Stephen E. Sandherr, the association’s chief executive officer.