The average price of a gallon of regular-grade gasoline fell 7 cents nationally over the past two weeks, to $2.62.
Industry analyst Trilby Lundberg of the Lundberg Survey said Sunday that the drop comes as flooded refineries continue to come back online after devastation caused by Hurricane Harvey.
Lundberg says she expects prices will continue to fall in the next few weeks.
Gas in San Francisco was the highest in the contiguous United States at an average of $3.18 a gallon. The lowest was in St. Louis at $2.19 a gallon.
The U.S. average diesel price is $2.51, down 2 cents from two weeks ago.