Home prices saw broad gains at the end of the summer selling season, with values rising even in hard-hit regions of the country such as Detroit, Las Vegas, Phoenix and South Florida, according to new data released Tuesday.

Real estate values rose 2 percent across the country in August compared with the same month a year earlier, according to the Standard & Poor’s Case-Shiller index. Of the 20 metropolitan regions tracked by the index, only the Seattle area experienced a decline, edging down by 0.1 percent.

Homes in the Washington region, where prices have generally held up through the economic downturn, posted a 1.1 percent increase in value over July and a 4.3 percent gain over August 2011.

The broader data show that the housing market, which experienced some of its worst years since the Great Depression after the financial crisis of 2008, is finally finding its footing, some analysts said.

“The sustained good news in home prices over the past five months makes us optimistic for continued recovery in the housing market,” David M. Blitzer, chairman of the index committee at S&P Dow Jones Indices, said in a statement.

Others cautioned not to make too much out of the report.

Stan Humphries of the real estate Web site Zillow warned that Case-Shiller is mimicking what other indicators already have shown — that the housing market is improving after hitting bottom. He said the modest gains could be short-lived.

“The reality is that the annual comparison for Case-Shiller is a bit of a mirage since home values were down so sharply in the back half of 2011,” Humphries said in an e-mail.

The gains mean average home prices are back to their 2003 levels, though still down about 30 percent from their 2006 peak.