Why are gas prices so high in CA in spring and summer? What’s behind cost spikes
Summer is around the corner, which means many Californians are beginning to plan road trips and vacations.
However, upcoming changes in gas prices could make travelers hesitant about hitting the road.
“Traditionally, gasoline prices are at their lowest during the first week of February and then begin to climb, often peaking right before Memorial Day,” said the National Association of Convenience Stores, a trade association representing the convenience and fuel retailing industry.
Why do gas prices increase as the weather gets warmer? And when will fuel start getting cheaper?
Here’s what to know:
Why are gas prices so high in California?
On average, California residents paid $2.2 billion more for gasoline in 2023 than the national average, according to the California Energy Commission.
Drivers in the Golden State regularly pay more at the pump than the rest of the nation due to environmental restrictions, higher taxes and a decreasing number of regional refineries, CNN reported in January.
California has its own special fuel blend that emits fewer greenhouse gases when burned, according to the California Energy Commission.
Gasoline sold by California retailers is made up of 90% petroleum-based gasoline and 10% ethanol, as specified by the California Air Resources Board, the energy commission said.
Under the Clean Air Act of 1970, California is the only state that can set stricter emissions standards than the federal government.
California’s high gas taxes also “(push) up the price of gasoline at the pump,” Derek Stimel, associate economics professor at UC Davis told the Fresno Bee in February.
More than 90% of gasoline consumed in California comes from in-state refineries, according to the California Energy Commission.
Of the 14 oil refineries in California, 11 produce transportation fuels that meet California’s environmental standards, the energy commission said.
Unplanned refinery outrages can contribute to increases in gas prices, according to the state agency.
Why gas is more expensive in spring and summer?
The kind of gasoline you put in your vehicle — and how much it costs — can depend on when you fuel up your car.
“As spring approaches, refineries are beginning their transition to summer blend fuel, which often results in higher prices this time of year,” AAA said in a February news report.
The summer ozone season falls between June 1 and Sep. 15.
During the winter, fuels have a higher Reid vapor pressure, meaning the vapor pressure evaporates more easily and allows cars to start during colder temperatures, explained the National Association of Convenience Stores, a global trade association representing the convenience and fuel retailing industry.
To avoid “increased emissions and the formation of smog,” retailers switch to a so-called summer blend with a lower Reid vapor pressure when the weather grows warmer, according to the trade organization and Amsoil, a manufacturer of synthetic lubricants and fuel additives.
Summer-blend fuel is more expensive to make than winter-blend fuel because it requires an longer production process that results in a lower yield overall, the National Association of Convenience Stores said.
The price difference between the two blends can be as much as 15 cents per gallon, the trade organization said.
When do gas stations make switch to summer-blend fuel?
According to the National Association of Convenience Stores, refineries switch over to summer-blend production in March and April.
In most parts of the United States, retailers have until June 1 to switch to summer-grade gas, the trade group said, although many start selling the blend as early as May 1.
“This date is the most important reason that seasonal gas prices tend to peak in May,” the trade organization said.
Why else do fuel prices increase as weather warms?
Demand for gas is higher during the spring and summer, when people tend to plan more activities to take advance of better weather.
That puts pressure on gas prices, experts said.
“Historically, retail gasoline prices tend to gradually rise in the spring and peak in late summer, when people drive more frequently,” the U.S. Energy Information Administration said on its website.
When does gasoline start getting cheaper?
Gasoline prices typically decline during the fall when demand decreases and temperatures cool, according to the National Association of Convenience Stores.
Gas stations usually begin selling cheaper winter-blend fuels on Sept. 15, although some retailers may switch over soon as their summer-fuel inventories drop, the trade organization said.
“As a result of California’s warmer climate, the state uses summer-blend gasoline for a longer period during the year than elsewhere in the nation,” the California Energy Commission explained,
The season for summer-blend fuel in California tends to run through the end of October in Northern and Southern California, the convenience store trade group said.
How much does a gallon of regular gas cost in California?
As of Friday, April 11, the average price for a gallon of regular unleaded gasoline in California was $4.91, more than 40% higher than the national average price of $3.23 per gallon, according to AAA.
San Bernardino County had the cheapest overall gas prices in the state as of Friday, with stations charging an average of $4.73 per gallon, AAA said.
The most expensive fuel could be found in Mono County, where regular gas cost $5.85 per gallon on average as of Friday.
A month ago, the average statewide cost of a price of regular gas was $4.694, according to AAA, indicating that prices are trending upward as California gets deeper into spring.
Where to find cheapest gas in Sacramento area?
According to GasBuddy, these were the five cheapest places to get gas in the Sacramento area for a gallon of regular gas as of Friday, April 11:
- Quik Shop, 8696 Greenback Lane in Orangevale: $4.15 per gallon of regular gas
- 76, 300 West St. in Woodland: $4.23
- Kwik Serv, 150 Placerville Drive in Placerville: $4.24
- Speedway, 519, Placerville Drive in Placerville: $4.24
- Quik Stop, 1400 East Main St. in Woodland: $4.25
Most affordable gas in Modesto?
In the Modesto area, these five gas stations had the lowest gas prices as of Friday, April 11, according to GasBuddy:
- Sinclair, 2805 Earl St. in Modesto: $4.15 per gallon of regular gas
Marathon, 1606 Sisk Road in Modesto: $4.19
- Kwik Serv, 1700 Yosemite Blvd. in Modesto: $4.19
- Sinclair, 1149 West F St. in Oakdale: $4.19
- BZ Mart, 1510 Miller Ave. in Modesto: $4.21
Which Fresno gas stations have lowest fuel prices?
For the city of Fresno, these gas stations had the cheapest gas per gallon as of Friday, April 11, according to GasBuddy.
- EZ Trip, 2171 West Shaw Ave. in Fresno: $3.87 per gallon of regular gas
- Fuel Up!, 1021 East Shaw Ave. in Fresno: $3.99
- Sinclair, 1014 East Bullard Ave. in Fresno: $4.07
- Fuel Up!, 4994 East Ashlan Ave. in Fresno: $4.09
- Costco, 7100 North Abby St. in Fresno: $4.14
Cheapest gas in Merced?
According to GasBuddy, thesee were the top five spots for low fuel prices in the Merced area as of Friday, April 11:
- Star Gas & Mart, 1970 East Childs Ave. in Merced: $4.29 per gallon of regular gas
- Kwik Serv, 1405 Davis St. in Livingston: $4.31
- Delhi 5 Star, 15406 August Ave. in Delhi: $4.35
- Quik Stop, 401 Joseph Gallo Court in Livingston: $4.35
- Shell, 1720 R St. in Merced: $4.39
Where to find cheapest gas in SLO County
These were the five best places to find cheap gas in San Luis Obispo County as of Friday, April 11, according to GasBuddy.
- San Paso Truck Stop, 81 Wellsona Road in Paso Robles: $4.49 per gallon of regular gas
- Fastrip Fuel & Wayside Liquors, 710 Creston Road in Paso Robles: $4.53
- Costco, 1540 Froom Ranch Way in San Luis Obispo: $4.55
- Conserv Fuel, 254 Santa Rosa St. in San Luis Obispo: $4.55
- USA Gasoline, 1798 Main St. in Morro Bay: $4.55
This story was originally published April 13, 2025 at 5:00 AM.
