Las Vegas led the cities with an increase of 2.9%, its highest since August 2004. Detroit and Los Angeles followed with gains of 2%, according to Standard Poors.
However, price increases peaked in April during the spring selling season, according to SPs index committee chairman David Blitzer.
Since then, home prices continue to rise, but at a slower pace each month, he says. This month 16 cities reported smaller gains in August compared to July.
Overall, home prices are up 12.8% since August 2012, according to the SP Case-Shiller report.
Home prices in all 20 cities are below their 2006 peaks. Boston and Charlotte are the two cities closest to their peaks with only 8% to 9% to go, according to the report released Tuesday.
Las Vegas is still down 47% from its peak level.