Most of the rise is from births, but immigration shows an increase, particularly from abroad. The Bay Area has the largest boost while L.A. County's growth is more modest.
California's population grew by roughly 332,000 people in the last fiscal year — its biggest increase in nearly a decade, according to new California Department of Finance estimates.
"It's a sign that our economy is recovering," said Hans Johnson, a Public Policy Institute of California demographer. "But it's still pretty slow growth."
The estimated population rose 0.88%, exceeding 38.2 million as of July. Most of that growth was "natural increase" — births minus deaths. But those numbers stayed roughly the same as in recent years, while immigration has increased.
Between July 2012 and July 2013, roughly 170,000 more people came to California from other countries than left, according to the estimates. At the same time, nearly 103,000 more residents left California for other parts of the United States than came into the Golden State. The result was a net increase of 66,000 people who came to California from elsewhere.
Compared with population trends in recent years, "the big change was the increase in the number of foreign immigrants," said Stephen Levy, director of the Center for Continuing Study of the California Economy.
The Department of Finance said that the growth, despite being slow, was the fastest that California has seen since 2003-04, well before the recession. Johnson said that even before the latest downturn, California had grown slowly because high housing prices pushed away families during boom years.
"At least we're not in a bust anymore," USC professor of public policy Dowell Myers said. "But the return to normal is still crawling at a snail's pace."
The fastest-growing counties were in the Bay Area — Alameda and Santa Clara — which grew by 1.68% and 1.47% respectively, according to the new estimates. Economists said the tech industry has helped propel those gains. Growth was slower in Los Angeles County, which gained about 74,000 people — an increase of 0.75%.
In Los Angeles, future growth "is really going to be dependent on getting our local economy fully back on track," said Robert Kleinhenz, chief economist for the Los Angeles County Economic Development Corp. Key sectors such as transportation and logistics have yet to fully recover, he added.
Los Angeles County experienced a net increase of about 55,900 people from other countries, offset by nearly the same net total who moved to other states, the estimates show. The continued flow of people to other parts of the U.S. concerned some economists.
"I would suspect people are leaving because of the cost," said Perry Wong, an economist with the Santa Monica-based Milken Institute. In Los Angeles and across the state, "I would like to see us keep our talent — but add the international talent at the same time," Wong said.
The Department of Finance creates its annual estimates using an array of government data, including records from the California Department of Motor Vehicles, housing data from local governments and information about federal income tax returns from the Internal Revenue Service.
The numbers factor in estimates of immigrants who are in the country illegally, based on Pew Research Center and Department of Homeland Security estimates.