PHOENIX -- The Valley's housing market is up more than 10 percent from last May, a new report said.
The Standard & Poor's/Case-Shiller 20-city home price index released Tuesday said the Valley's real estate market has increased 20.6 percent between May 2012 and May 2013.
Phoenix's ranking was the third-highest in the index, trailing San Francisco, which has seen a 24.5 percent increase, and Las Vegas, which has seen a 23.3 percent increase.
The price increases were widespread. All 20 cities showed gains in May from April and compared with a year ago.
Nationwide, the housing market is up by an average of 12.2 percent, the largest annual gain since March 2006.
Svenja Gudell, senior economist at Zillow, a home price data provider, said a big reason for the recent price gains is that foreclosed homes make up a smaller proportion of overall sales. Foreclosed homes are usually sold by banks at fire-sale prices.
"Typical home values have appreciated at roughly half this pace for the past several months, which is still very robust," Gudell said.
Gudell said higher mortgage rates and a likely increase in the number of homes for sale in the coming months should slow the pace of price gains and stabilize the housing market.
The index covers roughly half of U.S. homes. It measures prices compared with those in January 2000 and creates a three-month moving average. The May figures are the latest available. They are not adjusted for seasonal variations, so the monthly gains reflect more buying activity over the summer.
Despite the recent gains, home prices are still about 25 percent below the peaks they reached in July 2006. That's a key reason the supply of homes for sale remains low, as many homeowners are waiting to recoup their losses before putting their houses on the market.
The Associated Press contributed to this report.