From Standard and Poor’s:

Record Low Annual Declines Recorded in May 2008 for the S&P/Case-Shiller Composite Home Price Indices

Data through May 2008, released today by Standard & Poor’s for its S&P/Case-Shiller1 Home Price Indices, the leading measure of U.S. home prices, show annual declines in the prices of existing single family homes across the United States generally continued to worsen in May 2008. For the second straight month, all 20 MSAs posted annual declines, nine of which are posting record lows and 10 of which are in double-digits. Both the 10-City Composite and the 20-City Composite are reporting record low annual declines.

Data junkies can find the underlying index data here:

S&P/Case-Shiller Home Price Indices - May 2008 (XLS)

From CNBC:

Home Prices Fall in May, Erasing Four Years of Gains

Prices of U.S. single-family homes plunged at a record pace in May from a year earlier, with each of the 20 regions monitored showing annual declines for a second month, according to the Standard & Poor’s/Case Shiller home price indexes reported on Tuesday.

From Bloomberg:

S&P/Case-Shiller 20-City Home-Price Index Fell 15.8% in May

Home prices in 20 U.S. metropolitan areas fell at a faster pace in May, indicating the three-year housing slump has not stabilized, a private survey showed today.

The S&P/Case-Shiller home-price index dropped 15.8 percent from a year earlier, the biggest decline since records began in 2001, after decreasing 15.2 percent in April. The gauge has fallen every month since January 2007.

Stricter loan rules, rising mortgage rates and an increase in foreclosures are making it more difficult for prospective buyers to get financing, hurting home sales. The prolonged real-estate slump, along with higher fuel prices a shrinking job market, is weighing on consumers and the economy.

“Prices will need to fall further to help stimulate demand,” Joshua Shapiro, chief U.S. economist at Maria Fiorini Ramirez Inc. in New York, said before the report. “With supply overhang still huge and mortgage financing tougher to obtain, home prices are going to decline considerably further in the quarters ahead.”

Home prices decreased 0.9 percent in May from the prior month after declining 1 percent in April, the report showed. The figures aren’t adjusted for seasonal effects so economists prefer to focus on year-over-year changes instead of month to month.

The index was forecast to fall 16 percent from a year earlier, after a previously reported 15.3 percent drop in the 12 months ended in April, according to the median forecast of 25 economists surveyed by Bloomberg News. Estimates ranged from declines of 14.8 percent to 17 percent.

From MarketWatch:

Home prices fall 15.8% in past year: Case-Shiller

Home prices in 20 major U.S. cities have fallen a record 15.8% in the past year, as prices fell in all 20 cities tracked by the Case-Shiller home price index, Standard & Poor’s reported Tuesday. Home prices fell 1% in May compared with April. Prices in seven cities are down more than 20% in the past year.

From the AP:

S&P: Home prices drop by record 15.8 pct. in May

A closely watched housing index shows home prices fell by the steepest rate ever in May, as the housing slump continued to deepen nationwide.
The Standard & Poor’s/Case-Shiller 20-city index, released Tuesday, is off 15.8 percent for May compared with a year ago, a record decline since its inception in 2000. The narrower 10-city index has fallen 16.9 percent, its biggest decline in its 21-year history.

No city in the Case-Shiller 20-city index saw price gains in May, the second straight month that’s happened. The monthly indices have not recorded an overall home price increase in any month since August 2006.