The Local Lowdown

Quick Take:

• Single-family median prices diverged again in September, with San Mateo County up 6.50% year over year to $2,129,000 while Santa Clara County slipped 2.56% to $1,900,000.
• Condo pricing is where the real softness lives, with all three counties posting year-over-year declines, including double-digit drops in Santa Clara and Santa Cruz.
• Single-family inventory is down 9.72% year over year at 2,007 listings, yet it ticked up for the first time in months as fall listings arrived.
• Single-family homes continue to move in roughly 12 days in San Mateo and Santa Clara Counties, while Santa Cruz remains the slower, more deliberate market at 29 days.

San Mateo keeps climbing while Santa Clara drifts sideways

The single-family picture across Silicon Valley stayed split as summer gave way to fall. San Mateo County led the way with a median sale price of $2,129,000 in September, a 6.50% increase over last September's $1,999,000 and a 3.2% bump from August. That keeps San Mateo comfortably in the $2.1 million range it has held since March, a meaningful step up from the $1.9 million band it occupied through most of late 2025. Santa Clara County told a flatter story, with the median landing at $1,900,000, down 2.56% year over year even as it recovered modestly from August's $1,850,000. Santa Cruz County's median of $1,250,000 is up a slim 1.23% from a year ago, though it gave back ground after three consecutive months at or above $1,350,000.

The condo market is the clear soft spot. San Mateo County condos closed at a median of $740,000, down 3.77% year over year and off nearly 10% from August's $820,000. Santa Clara County condos fell 17.05% year over year to $627,500, the lowest reading in the three-year series. Santa Cruz County condos dropped 20.95% to $585,000, a steep move down from August's $800,000 and a reminder that the county's small condo sample can swing hard from month to month. Taken together, attached housing is absorbing the price pressure that detached homes in San Mateo have so far avoided.

Inventory stays thin, but fall listings offered a small opening

There were 2,007 single-family homes for sale across Silicon Valley in September, down 9.72% from the 2,223 available a year ago. What makes this month interesting is the direction of travel: for-sale inventory actually rose from 1,928 in August, the first increase since the spring peak of 2,217 in May. Sellers came back out, with 1,579 new single-family listings hitting the market, up sharply from August's 1,453 though still 4.88% below last September. Closed sales told a quieter story at 1,121, a 7.13% year-over-year decline, which suggests buyers were a bit more selective heading into the fall than the headline inventory squeeze might imply.

The condo side mirrored that pattern. There were 808 condos for sale, down 8.49% year over year, with the count edging up from 793 in August. New condo listings jumped to 388, a 13.12% increase over last September and the strongest month since May. Sold condos came in at 224, off 10.40% from a year ago. The combination of more new supply and fewer closings is exactly the dynamic showing up in those falling condo medians.

Detached homes still move in two weeks, condos tell a mixed story

Speed remains the defining feature of the detached market here. San Mateo County single-family homes averaged 12 days on market in September, a 7.69% improvement over last year's 13 days and consistent with the 10 to 14 day range that has held all year. Santa Clara County also posted 12 days, unchanged from last September. Santa Cruz County continues to march to its own rhythm at 29 days, flat year over year but notably slower than the 17 days recorded in August, a seasonal pattern that also showed up last fall.

Condos were far less uniform. San Mateo County condos sold in 25 days, a substantial 37.50% improvement over last September's 40 days and the fastest pace since the spring. Santa Clara County moved the other way, with condos averaging 38 days, up 35.71% from 28 days a year ago and the slowest showing since the January spike. Santa Cruz County condos averaged 39 days, down 7.14% year over year, an improvement that is genuine but still leaves the county's attached segment as the region's most patient market.

Silicon Valley's detached market is still firmly in sellers' hands

When determining whether a market is a buyers’ market or a sellers’ market, we look to the Months of Supply Inventory (MSI) metric. The state of California has historically averaged around three months of MSI, so any area with at or around three months of MSI is considered a balanced market. Any market that has lower than three months of MSI is considered a seller’s market, whereas markets with more than three months of MSI are considered buyers’ markets.

By that measure, the single-family market across most of Silicon Valley remains decisively tilted toward sellers. San Mateo County sits at just 1.3 months of supply, a 31.58% decline from last September's 1.9 months and a level that leaves buyers with very little room to negotiate. Santa Clara County holds at 1.7 months, unchanged from a year ago and steady for three straight months. Santa Cruz County is the outlier at 3.7 months, technically buyers' territory, though that is down 15.91% from last September's 4.4 months and the county has been grinding tighter year over year all season. Condos are the more balanced to buyer-friendly segment: San Mateo County sits right at the 3.0 month balance point, down 21.05% from a year ago, while Santa Clara County at 3.8 months and Santa Cruz County at 4.0 months both favor buyers, with Santa Cruz improving a dramatic 31.03% from last September's 5.8 months. The takeaway for the fall is straightforward. Buyers chasing a detached home in San Mateo or Santa Clara should expect to compete and move fast, while anyone shopping for a condo has more leverage than they have had in years!

Local Lowdown Data