Seattle-area home-price trends are driven by this hot, hot city. Hint: It’s not Seattle.

After three straight months of negative growth, home prices around Seattle are on the upswing again.

Prices in King, Pierce and Snohomish counties rose by 0.7% since last year, according to the latest S&P CoreLogic Case-Shiller Home Price Index.

That growth can be attributed to Seattle’s southern neighbors.

In other words: It’s all about Tacoma, where homes are flying off the market.

Seasonal fluctuations aside, home prices in King and Snohomish counties have more or less leveled off in the past year. Only Pierce County continues to post high price increases, according to home-sales data from the Northwest Multiple Listing Service (NWMLS), which is more granular than Case-Shiller. The Case-Shiller index is based on a rolling average of home prices in all three counties.

And homes selling for less than roughly $420,000 saw the strongest increases in price over last year, 0.5%, compared to more expensive homes, Case-Shiller data shows. Most of the homes in Pierce County, where prices are around $384,500, fall into that category.

Meanwhile, prices on homes selling for more than $420,000 stayed largely the same since last year. That price point includes most of the homes in King and Snohomish counties, according to the NWMLS.

Nationally, home prices saw a 0.3% month-over-month bump. Phoenix posted the strongest home price gains among major metropolitan areas, with a 6.3% increase over last year.

“However, a shift in regional leadership may be underway beneath the headline national index,” said S&P Managing Director Philip Murphy, from cities in the Southwest to those in the Southeast. After Phoenix, the next three cities with the strongest growth are all in the Southeast: Charlotte, Tampa and Atlanta.

And surprisingly, Las Vegas, the city that last year knocked Seattle out of its nearly-two-year streak of posting the highest home-price gains, didn’t make an appearance this month in the ranks of the top three cities with the fastest-increasing prices. Las Vegas, which posted a 0.2% decline in home prices from last month, was dethroned as the nation’s hottest housing market in August.