Delta Air Lines (82.8%) returned as the leader in on-time performance (OTP) in August, according to the latest report from Cirium, a data and analytics provider. The top spot was briefly taken by Alaska Airlines the last two months. United Air Lines followed, with an OTP of 81.61% at the second spot. Alaska took third place, with an OTP of 81.52%.

After slipping for two months in a row, North American carriers’ average OTP turned around in August, increasing 6 percentage points from July to 71.8 percent, according to the report.

All but one of the qualifying North American carriers showed month-over-month improvement — Alaska Airlines dropped 0.5 percentage point — and each carrier surpassed the 60% marker. The carrier with the biggest gain was United, jumping 10.7 percentage points to 81.6%, putting it in second place behind Delta. Frontier Airlines, JetBlue and Air Canada each improved 8.8 percentage points from July but remained in the bottom three slots.

Globally, Avianca (86.86%) returned to the top spot after briefly losing that ranking to LATAM last month. Qatar Airways moved up and followed Avianca closely in the second spot, with an OTP of 85.77%. Iberia ranked third among the top-performing global airlines, with an OTP of 85.76%. Azul returned as a top performer in the global category, with an OTP of 85.37%.

In Europe, Iberia continued to lead the region. Norwegian Air Shuttle (84.61%) climbed to second place, while Austrian Airlines (81.09%) finished third. Air Europa (80.42%) made its debut this year among the top pe