On a year-over-year basis, national home prices, including distressed sales, fell by 5.2 percent in July compared to July 2010 – a contrast to the Massachusetts market, where prices rose 1.3 percent, according to the CoreLogic July Home Price Index.

Excluding distressed sales, year-over-year nationwide home prices declined by 0.6 percent in July compared to July 2010. In Massachusetts, prices excluding distressed sales – REO and short sales – rose 2.1 percent.

Of the top 100 Core Based Statistical Areas (CBSAs) surveyed by CoreLogic, measured by population, 86 are showing year-over-year declines in July, two fewer than in June.

"While July’s numbers remained relatively positive, particularly for non-distressed sales which have been stable, seasonal influences are expected to fade in late summer. At that point, the month-over-month growth will most likely turn negative. The slowdown in economic growth and increased uncertainty caused by the recent stock market volatility will continue to exert downward pressure on prices," said Mark Fleming, chief economist for CoreLogic.