U.S. airlines spent $6.66 billion on jet fuel in May, nearly double what they paid a year earlier, according to Bureau of Transportation Statistics data released Tuesday.
The May total marked another month of elevated fuel spending for carriers. In April, airlines spent $6.47 billion on fuel, the agency said.
The jump was not caused by a major increase in flying. Airlines used 1.627 billion gallons of fuel in May, slightly less than in May 2025. Fuel use in April was also down from the same month last year.
Instead, airlines paid much more for each gallon.
The average jet fuel price in May was $4.09 per gallon. That was slightly lower than April’s $4.11 per gallon, but far above the $2.21 per gallon airlines paid in May 2025.
Fuel is one of the biggest expenses for airlines, making carriers sensitive to sudden swings in energy markets. When fuel costs rise sharply, airlines often try to offset the increase through higher ticket prices, added fees, or reduced service on weaker routes.
The industry has already moved in that direction. Airlines around the world have raised fares, added fees, and cut some flights in response to higher fuel costs, according to the Associated Press report.
The surge followed a sharp rise in energy prices after fighting in the Middle East disrupted shipping through the Strait of Hormuz. The waterway is one of the world’s most important passages for oil and fuel shipments.
Prices have since pulled back from their spring peak after the United States and Iran reached an interim ceasefire agreement. But the situation remains unstable.
Three tankers were hit by projectiles Tuesday in the Strait of Hormuz, according to the British military. The United States also revoked a license that had allowed Iranian oil sales under the ceasefire agreement.
The fuel data comes as U.S. airlines prepare to release second-quarter earnings. Delta Air Lines is scheduled to report results Friday, with other major carriers expected to follow.
Investors will likely watch whether recent fuel-price declines are enough to ease pressure on airline margins after an expensive spring.
The Argus U.S. Jet Fuel Index showed jet fuel at $2.88 per gallon Tuesday across major airline hubs including Chicago, Houston, Los Angeles, and New York. The price moved below $3 per gallon on June 15 and has stayed below that level since.