King County September 2026 Condo Prices

King County condo prices diverged from the combined county figure in September 2026: the median closed-sale price fell 5.97% from a year earlier to $496,000, while the combined residential-and-condo median held at $850,000. NWMLS’s county tables give sellers reason to review their competitive position, but the median decline does not establish a matching loss of value for an individual unit.

Northwest Multiple Listing Service published its September market release on October 6, 2026. The comparisons below use September 2025 figures reported in that release, with active inventory measured at month-end.

What the combined median leaves out

The unchanged county median gives condo sellers an incomplete account of the market. NWMLS’s residential-only median also declined, but by a smaller 0.73%, to $949,975. The combined figure pools residential and condominium transactions; it does not describe either segment on its own. NWMLS’s separate category tables make that difference visible.

For condos, the lower median came with fewer transactions and more competing listings:

These are condominium figures from NWMLS’s King County reports, not totals for Seattle or the wider NWMLS service area.

The decline in pending sales shows that weaker activity extended beyond completed transactions to contracts. Together with rising inventory, that supports a more cautious asking-price strategy. The figures cannot quantify the concession, if any, a particular seller should make.

What seven months of condo inventory means

NWMLS calculates months of inventory by dividing month-end active listings by that month’s closed sales. King County’s 2,480 active condos divided by 352 closings produced 7.05 months of inventory, as reported in the October 6 commentary. Applying the same calculation to the year-earlier counts gives about 4.40 months.

Both movements pushed the ratio higher: listings increased while closings fell. Seven months describes how long the available stock would last at September’s closing pace if no additional listings arrived. It does not predict how long a particular condo will take to sell.

For negotiations, use the ratio as a reason to investigate buyers’ alternatives. A seller competing with several similar available units faces a different pricing decision from one whose layout, condition or location has few substitutes. County inventory cannot identify which situation applies.

Why the median cannot establish a unit’s value

A median identifies the middle price among the sales measured. Because different properties can sell in different periods, a lower median can reflect both price changes and a changing mix of transactions. The National Association of Realtors explains this sales-mix limitation in its May 5, 2026 report.

For example, a hypothetical month with a greater share of smaller, less expensive condos could show a lower median even without an equivalent decline for comparable units. The county table does not separate that effect from changes in underlying values. Our home-price reports distinguish measures that answer different pricing questions.

The county pattern was not uniform, either. NWMLS’s Seattle condo breakout recorded a $530,000 median, up 1.21% year over year, despite a 25% decline in closings and 8.30 months of inventory. Those figures apply to that Seattle breakout, not all of King County. They show that a rising median can coexist with weaker sales and substantial competition.

What to verify before adjusting a listing price

A pricing review needs evidence about both the unit and its building. Fannie Mae’s condo appraisal guidance calls for examining both, including the unit’s position, project amenities and association assessments. For a seller’s review, assemble evidence in four areas:

• Comparable units: Compare recent closed sales in the building and competing projects, checking size, layout, floor, view, condition and parking rights. Our guide to choosing comparable condominium sales explains where a neighboring unit can mislead.
• Timing and terms: Record contract dates as well as closing dates, and verify seller credits or other concessions. Fannie Mae’s adjustment guidance requires market evidence for time adjustments and the effect of concessions; a credit’s cost does not automatically equal its effect on value.
• Building costs and condition: Obtain current dues, assessment notices, reserve information and repair records. Identify what changed since each comparable sale rather than assuming the building’s circumstances stayed constant.
• Available substitutes: Review similar active and pending listings, asking-price changes and marketing time. Keep asking prices separate from verified closing prices, and use broader local market research to frame the comparison.

Ask a local agent or appraiser to explain the evidence behind a proposed adjustment. If comparable units are securing contracts while yours remains available, investigate the differences in price, presentation and terms. If the strongest comparables support the asking price, weigh the cost of waiting against a reduction.