Home prices rose across 17 of 20 major metropolitan areas in August, according to the S&P/Case-Shiller Home Price Indices released Tuesday.

Prices were up 1.3% in the top 10 markets, with a Composite 10 Index reading of 157.93, and up 1.2% in the top 20, with the Composite 20 Index registering 146.0, from July to August on a non-seasonally adjusted basis.Seasonally adjusted, both composites were up 1%.

It was the seventh consecutive month that home prices have improved, S&P said. However, while the annual rate of decline has slowed, the Composite 10 remained down 10.6% and the Composite 20 down 11.3% from August, 2008.

Prices overall were down to Fall, 2003 levels. The declines from the price peak in second quarter, 2006 came in at 30.2% and 29.3% for the Composite 10 and 20, respectively, a marked improvement from -33.5% and 32.6% as of the market trough in April 2009.

Only three markets posted month-to-month declines: Charlotte was down 0.4%, Cleveland was down 0.5% and Las Vegas was down 0.3%. The rate of decline in all three, however, slowed from July. On a year-over-year basis, Las Vegas continues to lead the declines with -29.9% with the index at 105.78, followed by Phoenix at -25.1% and 108.41, and Detroit at -22.6% and 71.59.An index of 100 is based on home prices in January, 2000.

Among other markets, Atlanta was up 1.0% month to month and down 10.6% year over year; Boston up 0.9% and down 4.2% respectively; Chicago up 1.7% and down 12.7%; Dallas up 0.2% and down 1.2%; Denver up 1.9% and down 1.9%; Los Angeles up 1.6% and down 12.0%; Miami up 1.1% and down 18.8%; Minneapolis up 3.2% and down 13.7%; New York up 0.5% and down 9.6%; Portland up 0.3% and down 12.5%; San Diego up 1.6% and down 8.9%; San Francisco up 2.8% and down 12.5%; Seattle up 0.1% and down 14.7%; Tampa up 0.4% and down 17.7%; and Washington up 1.4% and down 7.9%.

"While many of the markets remain down versus this time last year, the relative rate of decline has shown some real improvement," said David M. Blitzer, chairman of the Index Committee at S&P. "California, in particular, has seen some real positive prints in recent months. We see this general trend whether you look at the as-reported data or the seasonally adjusted figures."

He warned, however, that the expiration of the federal first-time homebuyer tax credit Nov. 30 and mounting joblessness could "have a dampening effect on home prices."

Learn more about markets featured in this article: Los Angeles, CA.