"It doesn't bode well for the consumer. By April or May you might see some isolated instances where you're seeing $5 (per gallon)" gas, said Jeff Spring of the Automobile Club of Southern California.
The price of gasoline in the state jumped 5 percent in the past week and 9 percent in the past 30 days, the Los Angeles Times reported Tuesday. On Monday it reached a statewide average of $4.031 per gallon.
AAA said the national price for a gallon of unleaded gasoline rose Tuesday to $3.57 per gallon.
The oil market is currently being buffeted by tensions in the Middle East and by an improved outlook economically in the United States and elsewhere.
Iran recently said it would stop sending oil to the Netherlands, Greece, Portugal, Spain, Italy and France after the European Union agreed to join in international sanctions against Iran for the country's alleged nuclear weapons program.
Iran also said it may decide to ban exports to other countries.
In California, the prices of motor-grade gasoline is also being pushed by the higher operation costs of the state's refineries, which are required to produce cleaner-burning gasoline, the newspaper said.
"Consumers have done what we're supposed to do, and the way the refineries in California responded is by producing less gasoline. And at the same time they began exporting their surplus to South America because this industry thrives on tight supply," said Charles Langley of the watchdog group Utility Consumers' Action Network.
Oil prices are also supported by higher demand. Recent U.S. reports on jobs and manufacturing have given rise to optimism about an economic recovery.
In addition, EU finance leaders Tuesday agreed to provide debt-burdened Greece with $172 billion in emergency loans, which could give rise to confidence in investments in the eurozone, possibly increasing demand.
China recently loosened lending regulations, which means banks there can lend more, another sign demand could increase.