Contra Costa County drivers are paying an average of $5.58 per gallon for regular gasoline, a 14-cent jump in a single week, as crude oil instability and rising summer demand push California pump prices further above the national average.
The county-wide average climbed from $5.44 on July 17 to $5.58 on July 24, according to AAA Mountain West Group data reported by Contra Costa News. California's statewide average hit $5.64 on July 31, up 7 cents from the prior week and $1.16 more than the same time last year.
The national average, by comparison, held steady at $4.09. That means California drivers are paying more than $1.55 extra per gallon compared to the rest of the country.
California remains the most expensive gasoline market in the nation, followed by Hawaii at $5.46. The cheapest gas is in Indiana at $3.56 per gallon, a gap of more than $2 from what drivers here are paying.
Why prices are rising
Aldo Vazquez, spokesperson for AAA Mountain West Group, pointed to geopolitical tension as the primary cause. "Rising crude oil prices are behind the spike at the pump," Vazquez said in the group's July 24 fuel report. "Volatility along the Strait of Hormuz and instability in the region have pushed oil prices into the $90 per barrel range and could continue driving up costs during the second half of the summer."
West Texas Intermediate crude oil rose $5.20 to settle at $84.46 a barrel at the close of trading the week of July 28, according to Energy Information Administration data cited by AAA. U.S. crude oil inventories dropped 7.2 million barrels from the previous week to 404.5 million barrels, about 7% below the five-year average. Gasoline demand also ticked up, rising from 8.94 million to 9.04 million barrels per day.
A volatile year at the pump
Contra Costa County prices have swung sharply in 2026. The county average started the year at $4.23 on Jan. 9, peaked at $6.22 on May 8, then fell back to $5.44 in early July before rebounding to $5.58 on July 24.
Among Bay Area cities, San Francisco had the highest average at $5.83 per gallon as of July 31, followed by Oakland at $5.65 and San Jose at $5.63.
Transit ridership rising alongside prices
The pain at the pump appears to be pushing some commuters onto buses. County Connection, the public bus system serving central Contra Costa County including Walnut Creek, reported nearly 240,000 riders in March 2026, its strongest March since 2019. Saturday ridership was 36% higher than in March 2019.
What's ahead
Vazquez said in the July 31 report that August brings some relief as road trips wind down and fall routines begin, but added that elevated crude oil prices could prevent that seasonal shift from starting on schedule. Drivers filling up premium will pay even more: California's average for premium gasoline was $6.08 per gallon as of July 31, and diesel stood at $6.91.
