Utah gasoline prices jumped unexpectedly over the past month, rising 14 cents per gallon for unleaded regular.

The sharp increase means Utah motorists, who only a month ago were enjoying the fifth lowest price in the country, are now paying the 10th highest price in the nation to fuel their automobiles.

Those who track Utah's gasoline prices are at a loss to explain the unusual late winter surge.

"This is the time of year when gasoline prices in Utah are typically lower than the rest of the country," said AAA Utah spokeswoman Rolayne Fairclough. "The increase is puzzling since there is an abundance of supply and demand is low."

The average price for a gallon of unleaded regular gasoline in Utah now stands at $2.74 a gallon, 14 cents higher than last month and $1.03 a gallon higher than last year at this time, according to AAA Utah.

Currently, the average price nationally for unleaded regular is $2.64. That is 11 cents lower than last month and 72 cents per gallon more than a year ago.

It isn't unusual for Utah gasoline prices to begin rising slowly in February with an upward trend continuing through September, said John Hill, state director for the Utah Petroleum Marketers and Retailers Association.

"This is the time of year when [Utah's] refineries begin shutting down some of their [crude] processing units for their annual maintenance," Hill said.

And he suggested maybe some of those refineries are holding a bit of supply off the market to build their inventories so they can take care of their customers during their scheduled down time.

Still, a sharp price jump in February is highly unusual.

And Fairclough noted in a statement announcing the result of AAA Utah's monthly gasoline price survey that even the price of crude oil, which represents about 57 percent of the cost of a gallon of gasoline, doesn't appear to be exerting much influence nationally or locally.

"Last week, oil prices dropped to their lowest levels in nearly two months," she said, speculating the reasons behind that decline included a stronger dollar, concern about unemployment and a soft European economy.

"There also seems to be a growing realization that the rapid rise in the price of oil at the start of 2010 was market exuberance without a firm foundation," she said. "Oil supplies continue to be robust and demand is low due to the season and the extreme weather experience in many parts of the country."

Utah consumers are just as puzzled.

"I don't see any reason why prices should be going up," said Anthony Santos of Salt Lake City, who works in an electronics retail store and drives 30 minutes back and forth to his job each day. "The only thing that comes to mind is that the oil companies are just being greedy."