Gas prices are heading back up. The average price of gas in Arizona is up 29-cents a gallon from last week to $4.36 a gallon on average. Diesel fuel, however, is down two cents from last week to $4.89 a gallon. Triple-A spokesman John Treanor says tightening supply, refinery maintenance season and maybe Hurricane Ian reaction is leading to a spike. Treanor also says there are normal indicators of lower gas prices that exist. He says “most of the country is on the winter blend, that’s cheaper, the demand for gas is down, that’s a good sign and oil globally is at $80 a barrel or lower, which is the lowest it’s been since January.” In Flagstaff, gas is up four cents a gallon from last week to $4.13 a gallon, while diesel fuel is unchanged from a week ago, holding at $4.96 a gallon. In Prescott, gas us up just three-cents a gallon this week to $4.02. Diesel is down a cent to $4.99 a gallon.