U.S.home prices rose in August for the fifth straight month, according to a well-known index.

The S&P/Case-Shiller home price index, which tracks 20 major metropolitan areas, showed that prices rose from July by 0.9 percent, going up in 19 of the 20 cities tracked. OnlySeattlefailed to show a month-over-month rise.

The popular index has been trending upward, with home prices bolstered by dropping unemployment and low mortgage rates. ThePhoenixarea, hard hit by the real estate bubble burst in 2006, has had price increases of almost 19 percent in the past year, according to the index.Detroit(7.6 percent) andMiami(6.7 percent) have also been leading the way.