Operating in the shadows of its flashy neighbor, the East Bay housing market is playing a steady game of catch-up with Silicon Valley.

The median price of a single-family home now exceeds $1 million in a dozen East Bay cities and sales took dramatic, local leaps this summer — the number of single-family homes sold in Walnut Creek in August was up 49 percent from a year earlier.

Even so, pockets of affordability still can be found, particularly in Contra Costa County. In August, the median price of a single-family home was $390,000 in San Pablo. To the east in suburban Brentwood, the median was $561,000, up 16 percent year-over-year, yet affordable by Bay Area standards.

Still, regional and national trends played out across the East Bay, where the supply of single-family homes shrank in August, forcing prices up, sometimes dramatically — by 17 percent year-over-year in Hayward; and by 18 percent in Pleasanton, where the median price of a house was $1,200,000.

The pattern is likely to continue: “With schools in session, there will be even fewer homes on the market” as the year winds down, predicted Dave Stark, a spokesperson for the Bay East Association of Realtors, whose latest report crunches the numbers for dozens of East Bay cities. If the number of available homes continues to diminish, the law of supply and demand should kick in, driving prices still higher.

Here are some snapshots from Alameda and Contra Costa counties.

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Along the 880 Corridor, Fremont illustrates current trends. The supply of single-family homes in August was down 33 percent from a year earlier, while consumer demand pushed sales up 13 percent and the median price jumped 10 percent — from $935,000 in August 2016 to $1,030,000 this summer.

Alameda also was a hotspot. The supply increased year-over-year by 9 percent, while sales jumped 67 percent and the median rose 7 percent to $960,000.

On the other hand, Oakland’s numbers were less dynamic: Sales fell 2 percent and the median sales price stayed essentially flat at $746,000.

West Contra Costa County remained a pocket of relative affordability. Listings fell 25 percent in Richmond, but sales there jumped 39 percent and the median rose modestly – by 3 percent – to $460,000.

In Lamorinda, listings were consistently down, while sales and prices rose in all three cities. The supply fell 12 percent in Lafayette, while sales leaped 70 percent above the levels of August 2016 and the median rose 7 percent to $1,505,000. It reached $1,357,500 in Moraga and $1,512,500 in Orinda.

Here are two snapshots from Central Contra Costa County. Listings dropped 37 percent in Concord, where sales rose 9 percent and the median price increased 4 percent to $600,000. And these were the August numbers for pricier Walnut Creek: supply, down 28 percent; sales, up 49 percent; median sales price, up 4 percent to $1,065,000.

In the Tri-Valley, year-over-year prices rose everywhere. The median hit $805,000 in Livermore; $1,059,000 in San Ramon; $1,082,500 in Dublin; $1,200,000 in Pleasanton, as mentioned; $1,365,000 in Danville; and $1,665,000 in Alamo.

Finally, for those who can stand the commute, the Delta in eastern Contra Costa County remained affordable, though prices climbed there, too. The median sales price rose 3 percent to $434,000 in Antioch; 9 percent to $430,000 in Pittsburg; and the aforementioned 16 percent to $561,000 in Brentwood.