S&P said national home prices rose 2.1% in the year to August

The S&P Cotality Case-Shiller U.S. National Home Price Index rose 2.1% in the year to August, up from a 1.9% gain in July, S&P Dow Jones Indices said on Tuesday. The release says the 10-city composite rose 3.6%, up from 3.4%, and the 20-city composite rose 2.7%, up from 2.5%. The figures are not seasonally adjusted annual changes. The release also says home values fell in real terms for a 15th straight month, because August consumer prices rose 3.4%, about 1.3 percentage points more than the 2.1% home-price gain. That inflation comparison is the release’s.

Chicago had the largest annual gain among the 20 cities for a sixth straight month, at 6.7%, followed by New York at 6.2% and Cleveland at 4.3%. Seattle had the weakest reading for a third straight month, down 2.0%, followed by Las Vegas, down 1.3%, and Denver, down 0.8%. On the month, before seasonal adjustment, the national index fell 0.2% and the 10-city index fell 0.4%, while the seasonally adjusted versions rose 0.3% and 0.4%, the release says.

Rebecca Kaufman, associate director of commodities at S&P Dow Jones Indices, said the real-terms decline continued but the gap narrowed as nominal price growth strengthened. She said the usual post-summer slowdown was hiding some strength, because the unadjusted monthly declines and the adjusted monthly gains pointed different ways. She also said affordability remained difficult, with inflation at 3.4%, Brent crude near $100 a barrel in her description, and mortgage rates in what she called the mid-to-high 6% range. The oil and mortgage characterizations are hers, in the release. They are not a new price reading, and they are not a prediction.

Cotality said transaction delays at the recording office in Wayne County, the most populous county in the Detroit area, meant there was no valid August update for the Detroit index in this release. A July update was included in the tables. S&P said it will keep updating Detroit for the months that are missing sales.

The indexes track repeat sales of single-family homes. They are published on the last Tuesday of the month at 9:00 a.m. Eastern time. A change in an index is not a statement that a house should be bought or sold, and it is not a prediction of next month’s prices.