This morning, the S&P/Case-Shiller Home Price Indices showed that the not-seasonally adjusted August 10- and 20-City Composite declined -3.5% and -3.8% on a year-over-year basis, in line with Zillow’s forecast, which we released yesterday. On a seasonally adjusted monthly basis, the 20-City Composite  remained flat between July and August while the 10-City Composite fell 0.2%. The table below shows how our forecast compared with the actual numbers.

“Fourteen of the 20 markets showed negative monthly changes in prices on a seasonally adjusted basis, but only 8 of the 20 markets had monthly changes that worsened between July and August,” explains Zillow Chief Economist Stan Humphries. “These eight markets were Miami, Atlanta, Detroit, Las Vegas, New York, Cleveland, Portland and Seattle.”

Despite showing both monthly and annual depreciation, Humphries believes this isn’t the worst the housing market could have seen.

“Overall, it’s not a bad report on housing conditions, particularly since this housing downturn has given us a new appreciation for what “bad” really looks like. The Case-Shiller index is still falling on an annualized basis but is now seeing some improvement in the rate of annualized depreciation,” said Humphries. “This aligns with what Zillow sees in its own housing index which shows home values flat on a monthly basis in the Composite-10 and -20 markets and up just slightly in the August national index.”

To see how Zillow’s forecast of the July Case-Shiller indices compared, see our blog post from last month.