Gas prices up 28 cents in a month setting September record, diesel tops $6 for first time

As of September 11, 2026, the average price of regular unleaded gasoline reached $4.29 per gallon, marking a September record. This represents an increase of 28 cents within a single month. Additionally, diesel prices have surpassed the $6 mark for the first time. These price hikes reflect a significant upward trend in fuel costs during the month, impacting both regular gasoline consumers and diesel users as prices hit these unprecedented levels across the market.