US airlines have seen a significant increase in fuel spending, with May's total reaching $6.66 billion. This marks the second consecutive month that fuel costs have exceeded $6 billion.

The May figure represents an 84% increase from the same time last year. In April, airlines spent $6.47 billion on fuel, according to the Bureau of Transportation Statistics.

For more information on this trend and its potential impact, readers can refer to the full report from the Bureau of Transportation Statistics, as reported by KPRC 2 Houston.