The average price of a gallon of gas in Iowa fell 4.6 cents in the last week for an average of $2.99 per gallon. According to GasBuddy, gas prices in Iowa are 12.6 cents per gallon lower than a month ago and are 55.7 cents lower per gallon than a year ago. The average price of a gallon of gas in Wisconsin rose 5.5 cents in the last week for an average of $3.07 per gallon. Gas prices in Wisconsin are 12.2 cents per gallon lower than a month ago and are 37.9 cents lower per gallon than a year ago. The national average price for a gallon of gas is $3.17. The national price for a gallon of diesel dropped 1.2 cents in the last week for an average of $3.54 per gallon.