U.S. airlines spent $6.66 billion on jet fuel in May, the second straight month that fuel costs topped $6 billion, according to government data released Tuesday.
The May figure was 84% higher than a year earlier.
Airlines spent $6.47 billion on fuel in April, the Bureau of Transportation Statistics said.
The higher year-over-year spending has been driven mostly by pricier jet fuel rather than a significant increase in how much of it airlines consumed.
U.S. carriers used 1.627 billion gallons in May, down 0.6% from May 2025.
Consumption was also slightly lower in April compared with a year earlier.
The average price airlines paid for fuel in May was $4.09 per gallon, down slightly from $4.11 in April but 85% higher than the $2.21 they paid in May 2025, the agency said.
Airlines worldwide have responded to the jump in fuel prices by raising fares and fees and trimming flight schedules.
Fuel is typically one of the industry’s largest operating costs, leaving carriers particularly vulnerable to swings in energy prices.
The latest figures show the continued impact of the sharp rise in energy costs after the conflict in the Middle East started this year and disrupted shipping through the Strait of Hormuz, a key route for global crude and fuel supplies.
Fuel prices have eased from their spring highs after the U.S. and Iran reached an interim ceasefire agreement, offering some relief to airlines after a costly spring.
But the truce remains fragile.
Three tankers were struck by projectiles Tuesday in the Strait of Hormuz, according to the British military, and the U.S. revoked a license that had allowed Iranian oil sales under the agreement.
Delta Air Lines is set to report its second-quarter financial results on Friday, kicking off a wave of earnings reports from U.S. carriers.
Executives are expected to discuss how recent declines in fuel prices could affect the industry’s finances going forward.
The average price for a gallon of jet fuel was $2.88 across the key airline hubs of Chicago, Houston, Los Angeles and New York on Tuesday, according to the Argus U.S. Jet Fuel Index.
The price fell under $3 a gallon June 15 for the first time since early March and has remained below since.