Local gasoline prices are inching up again, but in a rare occurrence, California at-the-pump costs are lagging behind other states.

Monday's weekly report by SactoGasPrices.com, a GasBuddy.com website, said the average price of gas in the Sacramento area rose 2.6 cents to $3.74 per gallon over the past week.

Local prices rose 2.8 cents the previous week, breaking a 10-week string of declines.

The local average is 63.6 cents per gallon higher than it was one year ago, but 1.2 cents lower than a month ago.

Historically, California gas prices far exceed the national average, but not lately. The national average at-the-pump cost rose 2 cents to $3.69 a gallon over the past week.

On Monday, GasBuddy said the statewide average price was $3.79. The relatively slim difference was noted by Patrick DeHaan, senior petroleum analyst for GasBuddy.

A year ago, California was 35 cents above the national average," DeHaan said. "And I just saw where California has not appeared in the top three states in (gas) price in the lower 48 (states) since June 1. That's very rare. To put that in perspective, California was in the top three for 362 days in 2009 and 363 days in 2010."

On Monday, GasBuddy said California's average gas price was lower than that in six states in the lower 48 – Illinois, New York and Maine among them – plus Alaska, Hawaii and the District of Columbia. DeHaan said the key factor behind the relative affordability of California gas is stable supply.

"This year, California has maintained an above-average supply of gas," he said. "And with California's economy remaining sluggish, demand is not as high and supply will likely stack up."

Stocks of motor gasoline and gas-blending components in California have remained in the 29 million to 30 million barrel range since June 10, according to U.S. Energy Information Administration figures.

DeHaan said he expected California prices to remain in the $3.60 to $3.90 range the rest of the summer. He said small weekly increases are likely between now and Labor Day, "but I don't see anything rapid … unless something catastrophic happens."

The potential catastrophe DeHaan and other analysts are monitoring involves the debt ceiling talks in Washington, D.C. DeHaan said he's concerned about the impact on the dollar if the debt issues are not resolved soon. Since oil is priced in dollars, a weakened dollar makes crude oil more attractive to investors holding foreign money.

An investor rush in crude oil would likely drive up the per-barrel price, which in turn would send gas prices higher.

Crude is just below $100 a barrel as debt ceiling talks continue. Benchmark crude for August delivery dropped 67 cents to settle at $99.20 per barrel Monday on the New York Mercantile Exchange.

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