Sonoma County's median home price jumped to $479,000 in July as sales shifted dramatically from starter homes to properties in pricier neighborhoods.

The median price for a single-family home now stands at its highest level for any month in more than five years, according to The Press Democrat's monthly housing report compiled by Pacific Union International Vice President Rick Laws.

The median price rose 9 percent from June and 37.5 percent from a year ago. It hasn't been this high since January 2008, when it was recorded at $500,000.

But brokers said its rise last month was due mostly to a shift in the type of homes sold rather than a bump in property values. Sales of starter homes plummeted in July from a year earlier, while those in more expensive areas jumped sharply.

"Our upper-end sales have shot way up," said Stephen Liebling, manager of Coldwell Banker in Sebastopol.

Sales of homes priced under $400,000 were cut in half in July, declining to 158 from 325 a year earlier. Meanwhile, home sales above $400,000 increased 81 percent to 327 from 181 a year ago.

Even the number of homes selling above $1 million rose last month, climbing to 45 from 17 a year ago.

During the last housing boom, the county's median price soared to a record high of $619,000 in August 2005. But when the market crashed, the median tumbled to a low of $305,000 in February 2009.

Even two years ago, the July median price stood at $325,000.

But prices began rising more than a year ago, and for the past 13 months the median has consistently increased on a year-over-year basis.

The county's real estate market ended June with year-to-date sales of $1.34 billion, its best first half in six years.

In July, the market seemed less frantic, Liebling and two other brokers said. Sellers often still received multiple offers for their homes, but some attracted fewer prospective buyers.

"I feel like it's still hot and it's still good, but it's not quite as over the top as it was," said Cary Bertolone, a co-owner of Bertolone Realty in Santa Rosa.

July sales declined 4.2 percent from a year earlier to 485 single-family homes. Even so, the results remained the second-highest sales for the month in eight years, behind only July 2012.

Brokers remained uncertain whether the reduced activity might be due to the recent rise in mortgage rates or to a seasonal slowdown around the time of the county fair and the weeks before school starts.

Laws said the market took "a little lull" in July. But discussions with agents suggest that plenty of buyers are still looking and more sellers are planning soon to put homes up for sale.

"It sounds like there's going to be an uptick in properties coming to market," he said.

Foreclosures and short sales accounted for just 14 percent of county home sales last month, compared to 38 percent a year ago.

And the number of available homes for sale remained at the lowest level in at least a decade. Inventory amounted to less than a two-month supply at the current pace of sales, considerably less than the roughly six-month supply that experts say is needed for a balanced market.

In the Bay Area, buyers reported purchasing the most homes for July in eight years. Sales of houses and condos in the nine-county region rose 13.3 percent from a year earlier, according to San Diego-based DataQuick.

The Bay Area's median sales price increased 33.5 percent from a year earlier to $562,000. That was the highest since December 2007, when the median was $587,500.

"There's all this talk of a frenzy, but the fact is that we're still looking at a Bay Area housing market that is in the process of re-balancing itself, regaining lost ground," said John Walsh, DataQuick president. "As prices continue to rise, more homes will be put up for sale, easing the upward price pressure."