The Associated PressThis Aug. 22, 2011 photo, shows a new home with a sold sign, in Springfield, Ill. Home prices climbed in August for half of all major U.S. cities, including Portland.The nation’s home prices showed signs of good news in August, and this time Portland joined in the party — but without offering too much to celebrate.

The SP/Case-Shiller index was essentially flat in August, but 10 of the 20 metropolitan areas surveyed showed an increase in home prices. Among those is Portland, which showed an otherwise unremarkable increase of 0.1 percent that vanishes entirely with seasonal adjustment.

That’s five straight months of gains for half or more of the cities in the index — a “modest glimmer of hope,” said David M. Blitzer, SP’s index committee chairman.

But there’s good news, and then there’s housing good news.

Prices are still below a August year ago — 7.6 percent lower in Portland and 3.8 percent lower for the 20-city composite — though the year-over-year declines are smaller than those reported in earlier months this year, a sign of market stability.

“It’s better to have pneumonia than cancer,” said Bill Conerly, a Lake Oswego economist.

Most analysts agree the housing market appears to be at or near its low point. Tim Duy, an economist at the University of Oregon, said the fact that annual price declines are decelerating is encouraging.

“I’d be cautiously optimistic we’re nearing some kind of a bottom of home prices,” Duy said. “I’m less optimistic that you’re going to get some big surge upward here.”

The lingering problem, Conerly said, is a large inventory of houses amid a dwindling pool of potential buyers.

“We’re still in a situation of excess supply,” said Conerly, adding he included houses that aren’t listed for sale. “We simply have more housing units than we have households, and its going to be some time before we work that off.”

The Case-Shiller index is published on a two-month delay. According to local numbers gathered by the Regional Multiple Listing Service, the median home price in Portland fell slightly in August but then rose to $230,800 in September, a high point for the year so far.

Case-Shiller puts Portland’s home prices at levels seen in January 2005.

Low home values, of course, are great news for those with the means to buy a house.

“We’re probably going to bounce along the bottom for a little bit here, but you know, interest rates are amazingly low, and it makes for an amazing opportunity to buy a house,” Portland Realtor Rob Levy  of Prudential Northwest Properties said.

Also on Tuesday, a national housing index compiled by the Federal Housing Finance Agency showed a 0.1 percent decline in home prices, the first it reported since March.

The agency, the government regulator of Fannie Mae and Freddie Mac, calculates its index using loans backed by the two government-sponsored enterprises and says home prices have fallen 19.1 percent since February 2004.

— Elliot Njus