U.S. home prices edged up 0.9% in August as 19 of the 20 cities studied in the Standard & Poor's/Case-Shiller index posted positive monthly gains from July.  

The price jump beat analysts' expectations with Deutsche Bank forecasting a more modest 0.4% home price increase in August.

The 10-city composite index experienced an annual price gain of 1.3%, while the 20-city composite grew by 2% over last year.

Eighteen of the metros studied posted price gains from July, an indicator in line with reports of a market turnaround in real estate.

Phoenix stood out, posting its fourth consecutive double-digit annual price increase with values rising 18.8% from year ago levels.

Dallas remained strong, but unchanged with a 3.6% price increase, while Chicago's situation worsened as prices fell 1.6% annually in August.

Only three cities posted negative annual returns, Atlanta with a 6.1% drop in prices, New York with a 2.3% decline and Chicago with a 1.6% decline (see below, click to expand).

"The sustained good news in home prices over the past five months makes us optimistic for continued recovery in the housing market," said David Blitzer, chairman of the Index Committee at S&P Dow Jones Indices.

"News on home prices confirms other good news about housing. Single family housing starts are 43% ahead of last year’s pace, existing and new home sales are also up, the inventory of homes for sale continues to drop and consumer mortgage default rates are reaching new lows," Blitzer added.