Gas prices are down this week across Northern Arizona. Triple-A Arizona says the average price of gas in the state is $2.32 a gallon, which is down a cent from last week. In Flagstaff, gas is unchanged from last week, staying at $2.40 a gallon on average. Some stations are selling gas for $2.29 and lower. In Prescott, the average price of gas is down nearly a cent to $2.33 a gallon. Some stations are selling gas for $2.21 and lower. Officials say gas prices could fall due to the start of the school season.