Fuel costs for U.S. airlines jumped 78% in April to nearly $6.5 billion ​, compared with the year before, as the Middle East conflict drives up jet fuel prices, the U.S. Transportation Department said Monday.

Airlines' fuel costs were up 26% over March, and carriers used 2.6% less fuel in April than in March, USDOT said in a monthly report.

The cost per gallon of fuel in April was $4.11, up $1.81 from April 2025, USDOT added, a trend that has already had an impact on the sector. Spirit Airlines, an ultra-low-cost U.S. carrier, ceased operations in May, citing rising fuel prices as the reason.

Delta Air Lines, United Airlines, American Airlines, and Southwest Airlines account for about 80% of U.S. domestic flights.

The International Air Transport Association, which represents more than 370 airlines accounting for about ​85% of global air traffic, said in its annual report Sunday that ​it expects the industry to post a combined net profit of $23 billion in 2026, well ‌below ⁠a previous projection of about $41 billion and down from $45 billion in 2025.

Average fares for flights with a U.S. origin have risen this year by as much as 31% for domestic trips and 22% for international ones, when compared to ​the same weeks in ​2025, according to ⁠KAYAK search data.

The Middle East conflict, triggered by U.S. and Israeli airstrikes on Iran, has also forced airlines to reroute flights ​around closed or restricted airspace, increasing fuel burn and straining ​already ⁠tight capacity.

Oil prices have surged on fears of supply disruption, pushing jet fuel prices sharply higher and widening refinery margins, leaving airlines facing a steep jump in ⁠their highest ​cost.

IATA expects airlines' fuel bill to surge ​to about $350 billion this year from roughly $252 billion in 2025, with fuel accounting for nearly a third ​of operating costs.