These airlines had the worst on-time arrival record in July

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CHICAGO, IL - SEPTEMBER 19: An American Airlines jet prepares to land as a Spirit Airlines jet taxis at O'Hare International Airport on September 19, 2014 in Chicago, Illinois. In 2013 67 million passengers passed through O'Hare, another 20 million passed through Chicago's Midway Airport. The two airports combined moved more than 1.4 million tons of air cargo in 2013. (Photo by Scott Olson/Getty Images)
Photograph by Scott Olson — Getty Images

Spirit Airlines was the least punctual major airline in July, capping off a three-month streak of placing at the very bottom of on-time arrivals among other U.S. airlines. Only 68.7% of the airline’s planes arrived on time during July, compared to an industry average for the month of 78.1%.

Frontier Airlines ranked second-lowest for the month, with 71.4% of arrivals occurring on time, according to the U.S. Department of Transportation’s Air Travel Consumer Report released Thursday. Southwest and United Airlines tied for third-worst in on-time arrivals at 73.5%.

The good news is that all four of the month’s least punctual airlines had actually improved their performance from June. That month, Spirit Airlines was on time only 49.9% of the time, Frontier Airlines 67.6% of the time, and United and Southwest 66.3% and 72.5% of the time, respectively.

July showed marked improvements across the major airlines as a whole, beyond the laggards. Airplanes arrived on time 78.1% of the time–a 3.3% increase from the previous month and 2.5% increase from last July. Meanwhile, the overall cancellation rate of .9% was the lowest compared to that of any July in the past 21 years.

Major airlines have been under increased scrutiny for quality and fares in recent months due to a wave of consolidation that shifted a competitive market of nine large airlines into only four mega-carriers.