Iowa's average gas price has risen a quarter per gallon in the past month. The increase is blamed on an interruption of oil production during hurricane Harvey. The statewide average price of a gallon of regular is $2.55, up $.25 from a month ago. Cedar Rapids has the lowest prices statewide at $2.49 a gallon. Prices are highest in Des Moines, where drivers are paying $2.65 a gallon. The national average pump price is up $.16 from last week. Triple A says the average cost for a gallon of regular gas nationwide is $2.67.