The average price of a gallon of regular-grade gasoline rose 2 cents nationally during the past two weeks, to $2.35.
Industry analyst Trilby Lundberg said Sunday that despite the rise, gas prices are poised to dip slightly because crude oil costs are falling and refinery production is strong.
The national average is up 51 cents per gallon over the price a year ago.
Gas in San Francisco was the highest in the contiguous United States at an average of $3.03 a gallon Friday. The lowest was in Baton Rouge, Louisiana, at $2.03 per gallon.
The U.S. average diesel price is $2.58, up half a cent from two weeks ago.