Valley hit by spiking gasoline prices. Why? And when will they slow down?

Oil refinery maintenance in California is being blamed for rising gas prices that have surged by an average of at least 20 cents per gallon in the Valley in just one week.

Sunday, The average price of regular unleaded gasoline in Modesto/Stanislaus County was $3.83 per gallon, according to the AAA Gas Price report. Merced County was higher, at $3.91, and Fresno County higher still, at $3.93.

The Modesto price was up 24 cents a gallon from a week earlier, and up 65 cents from a month ago. On the date in 2018, the average price was $3.38, AAA reported.

The statewide average price for regular unleaded Sunday was $4 per gallon, and the nationwide average was $2.83.

“We are way over the price where we would be if not for these refinery issues,” Michael Blasky, a spokesman for AAA Northern California, said Thursday. “Typically we pay 70 cents to a dollar more than the national average.”

And the increasing pain at the pump isn’t likely to abate anytime soon, experts say. “We are in the middle of pretty exceptional refinery maintenance,” said Patrick DeHaan, head of petroleum analysis for “In addition to that, we’re in the midst of several unplanned outages that are causing the supply to tighten noticeably.”

GasBuddy’s list Sunday of the 10 California stations with the lowest prices included just one in Stanislaus County: RK Service Station at Yosemite Boulevard and H Street in Waterford, where regular unleaded was selling for $3.41 a gallon

GasBuddy’s Modesto site,, showed the lowest price Sunday was at a couple of QuikStop locations, one at Paradise and South Carpenter roads, the other at La Loma Avenue and Burney Street.

Becca and Nathaniel Webb were filling up a couple of vehicles at the La Loma station Sunday. It was convenient because it’s right around the corner from Nathaniel’s brother’s home, but the Webbs also know it consistently has good prices.

Becca said she watches the gas prices. “We were just talking about it this morning,” she said. “Up by our house — we live in Coulterville — it’s $4.19 a gallon, and it’s the only gas station up there. We just put like $10 in up there, then come down here.

“This is cheaper than (Arco) am/pm,” she said of the QuikStop, “and am/pm usually is the cheapest.”

Arco typically is a leader in low prices, but the cheapest in Modesto, according to GasBuddy, was $3.53 at the station at Fifth and I streets. Customers at the Arco on McHenry Avenue at Rumble Road were paying $3.67.

Jolana Jordan of Modesto said she looks around for low prices and had passed four other stations before pulling into Arco on Sunday afternoon. She agreed with Becca Webb that the chain usually can be counted on for value. The lower the price, the more fuel she pumps, Jordan said, but she almost never feels she can afford to fill her tank.

Chevron had the highest price per gallon in Modesto on Sunday: $4.15 at its stations at McHenry Avenue at Robin Hood Drive and at Sisk Road and West Briggsmore Avenue.

Both Blasky and DeHaan said refineries are in the process of changing their plants over for production of summer-blend fuels, both nationwide and in California.

Summer blends have higher oxygen content and evaporate less readily in fuel tanks, but California has more stringent standards. DeHaan referred to a California Energy Commission update reporting that refinery production of fuel for California motorists last week was down 10 percent from a week earlier.

Stockpiles of California-specific fuel, DeHaan added, were down 8 percent from a week prior and 19.3 percent below year-ago levels.

Flooding in the Midwest is adding to the problems, DeHaan said, because it has slowed down rail shipments of ethanol, “and ethanol is blended into almost every gallon of retail gasoline” in California.

Blasky said the refinery slowdowns are affecting companies in both northern and southern California, and added that a seasonal increase in demand for gasoline is adding another layer of stress on fuel supplies. “This is typically the time when we see the highest gas prices of the year, April, May, June and the summer travel season,” he said. “There’s not an easy solution for this. As demand picks up, it’s only going to drive the prices higher.”

DeHaan said he is hopeful that prices may stabilize or even start to come down this summer. “After the refinery issues level off, maybe in May, we may start to see some measure of relief,” he said.