U.S. airlines faced a sharp increase in fuel expenses in May, with costs reaching $6.66 billion—an 85% rise compared to the same month the previous year, according to data released Monday by the Department of Transportation. This surge is largely attributed to heightened tensions in the Middle East, which have driven up jet fuel prices.

In May 2025, airlines spent $3.62 billion on fuel, with the average cost per gallon at $4.09—an increase of $1.88 from May 2025. The April figure also saw a significant rise, with fuel expenses climbing approximately 80% to nearly $6.5 billion.

Although jet fuel prices have decreased by around 40% since peaking in April, geopolitical developments continue to influence the market. On Tuesday, oil prices rose more than 2% following reports of attacks on vessels near the Strait of Hormuz, a key route for global energy shipments. Late trading saw oil prices surge another 5% after the U.S. Treasury Department revoked a waiver that had permitted Iran to continue selling oil.

The rise in fuel expenses has led airlines to increase ticket prices and baggage fees while reducing flight schedules. Despite these measures, carriers have only been able to partially offset the higher fuel costs. Notably, airfares surged significantly following the outbreak of conflict involving Iran, but have yet to decline in response to recent drops in jet fuel prices.

The volatility in fuel costs reflects ongoing instability in the Middle East and its ripple effects on the aviation industry, underscoring the sensitive relationship between geopolitical events and airline operations.