The national average price for regular gasoline stood at about $4.52 a gallon on Monday, May 18, according to AAA, with California topping $6 a gallon while some Southern states remained near $4.
Analysts say geopolitical tensions, strong global demand for U.S. fuel exports and seasonal refinery pressures are keeping prices elevated heading into summer.
Industry experts expect continued volatility through the summer, though forecasts for later in 2026 still point to lower prices if supply disruptions ease.
AAA, which tracks gasoline prices in all 50 states, reports the national average price of regular gas is starting the week at $4.51 a gallon, the same as the day before. It’s actually a penny lower than last Monday.
But today’s average price is more than $1.50 per gallon higher than the day before the start of the Iran war. Industry analysts warn that relief may be limited as the summer driving season gets underway.
Prices vary dramatically by region, with California averaging more than $6.15 a gallon, while Texas and several Gulf Coast states were still below $4.
The increase reflects a combination of geopolitical instability, seasonal refinery issues and robust international demand for U.S. energy products.
Iran war was a game-changer
Patrick De Haan, head of petroleum analysis at GasBuddy, said global supply disruptions have transformed what was expected to be a relatively calm year for fuel prices into a volatile market.
“The same oil we rely on can be moved anywhere in the world,” De Haan told Business Insider, noting that record U.S. exports are contributing to tighter domestic supplies.
Industry analysts say tensions affecting oil shipments through the Strait of Hormuz have intensified concerns about global crude supplies, pushing up oil and gasoline futures. Refiners are also transitioning to more expensive summer fuel blends, while maintenance and outages at some U.S. refineries have tightened gasoline inventories.
West Coast feels the most pain
The Energy Information Administration’s latest fuel update showed particularly steep prices on the West Coast, where California gasoline averaged more than $7.22 a gallon in some regions. Diesel prices also remain elevated nationally, averaging about $5.64 a gallon.
Analysts warn that diesel prices could become an even larger economic problem because diesel fuels trucking, rail transportation and agriculture. MarketWatch reported that diesel prices are nearing record highs, raising concerns about broader inflation pressures as transportation costs work their way through the economy.
Despite the recent spike, some forecasters still believe prices could ease later in the year if geopolitical tensions stabilize and refinery operations normalize.
GasBuddy’s annual outlook released earlier this year projected a 2026 national average gasoline price below $3 a gallon, though that forecast was issued before the latest Middle East disruptions intensified.