The median price of houses sold in King County dipped in January to its lowest level since last March, according to statistics released Tuesday by the Northwest Multiple Listing Service.

But brokers and analysts downplayed the drop’s significance, attributing it to seasonal factors and an increase in sales of “distressed” homes rather than any broader market shift.

“The median is not reflective of what’s actually happening, at least in the close-in neighborhoods,” said Mike Skahen, owner of Lake Co. Real Estate in North Seattle.

Last month’s median single-family sale price was $350,000, up 11 percent from January 2012.

But prices were nearing their post-bubble bottom a year ago, and bounced back in spring. Until last month, the median had been hovering between $370,000 and $385,000 since June.

January’s median price was 8 percent lower than December’s. But that’s not unprecedented: The median has dropped or stayed the same between December and January every year since at least 2005.

Real-estate blogger Tim Ellis of Seattlebubble.com said that, while last month’s decline was somewhat surprising, he doesn’t read much into it.

“The houses that closed in January were on the market in November and December,” he said. “And people who are trying to sell their houses then, over the holidays, are usually pretty desperate.”

Glenn Crellin, associate director of research at the University of Washington’s Runstad Center for Real Estate Studies, concurred. “Traditionally you see lower prices in the middle of winter,” he said.

A change in the mix of houses sold also played a part in the drop in the median, an analysis of listing-service data by online brokerage Redfin suggests.

“Distressed” sales — bank-repossessed houses and “short sales” for less than what sellers owe lenders — accounted for a bigger share of sales last month: 24 percent, compared with 19 percent in December.

That’s meaningful because distressed houses generally sell for significantly less than “non-distressed” properties.

The median sale price of non-distressed houses remained virtually unchanged between December and January, according to Redfin. So did the median prices of bank-owned houses and short sales.

But the mix changed, helping drive the overall median down.

King County condo prices followed the same pattern as houses in January: The median sale price was $186,000, down nearly 10 percent from December but up more than 6 percent from January 2012.

In Snohomish County, the median house price in January was $258,500, down 6 percent from December but up 12 percent from January 2012.

Sales volume was up — about 25 percent year-over-year for both houses and condos in King County.

The total number of houses listed for sale in the county at the end of January remained at a near-record low, down 45 percent from the same time a year ago.

“It feels like it’s much worse,” Skahen said. A significant share of what’s listed isn’t attracting buyers because it’s priced too high or has other problems, he said.

Many homeowners aren’t listing their houses because they’re waiting for spring, or they think delaying will result in higher prices, Skahen said. Meanwhile, “we have three or four times as many buyers as we did a year ago. They feel like they’ve missed the boat.”

The January report did contain a few rays of hope on the inventory front for prospective buyers.

The total number of single-family homes on the market Jan. 31 was up slightly from Dec. 31, the first month-over-month increase since August. “That’s the most hopeful sign,” said Ellis.

Total inventory actually fell during January a year ago, a highly unusual event.

Also, there were more new listings last month than in the same month a year ago, the first time that’s happened since September.

Even so, Skahen said, a lack of inventory will continue to put upward pressure on prices until more houses are for sale.

It’s a matter of supply and demand. In North Seattle west of Interstate 5, for instance, there were 107 closed sales in January, 109 more pending sales recorded that haven’t yet closed — and just 92 houses for sale at the end of the month.

Inventory should increase by spring, Crellin said: “Folks who have been under water [owe lenders more than their houses are worth] have seen prices increase enough that they are at least level with the playing field,” he said.

That, plus continued local job growth, he said, make him optimistic about the housing market’s performance over the next few months, Crellin said.

Eric Pryne: epryne@seattletimes.com or 206-464-2231