Portland home prices climbed at a rate faster than any other major city except Seattle in July. But the gap between the two cities is widening as prices continue to accelerate in Seattle.

Portland saw home prices jump 0.6 percent in July and 7.6 percent year over year, according to the S&P CoreLogic Case-Shiller home price index.

While Portland once stood apart, leading the 20-city index in home-price gains for nearly 11 months in 2015 and 2016, it's now seeing year-over-year growth that better resembles places like Las Vegas (7.4 percent), Dallas (7.3 percent) and Detroit (7.3 percent).

"Consumers, through home buying and other spending, are the driving force in the current economic expansion," said David M. Blitzer, the chairman of S&P's index committee. While the gains in home prices in recent months have been in the Pacific Northwest, the leadership continues to shift among regions and cities across the country."

The Seattle metro area, however, led the index; prices grew 13.5 percent annually, the fastest rate that city has seen since 2005.

The national index saw prices climb 0.7 percent in July and 5.9 percent compared with a year earlier.

The Portland-area housing market, like much of the country, has seen prices continue to climb even as sales slow. That's due in part to a relatively slim inventory, leaving buyers with few options other than to bid prices higher on those homes that remain.

Blitzer said efforts to rebuild after hurricanes in Florida and Texas could make it more expensive to build elsewhere, increasing the supply crunch. Meanwhile, recent policies at the Federal Reserve could push mortgage rates higher.

The Case-Shiller index uses repeat sales of the same homes to estimate changes across the market. It's calculated using a three-month rolling average.

In Portland, the median price for a home that sold in July was $395,000. It fell slightly to $385,000 in August.

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus