U.S. airlines scheduled more than 647,600 flights in July, a record and surpassed 1 million flight delays for the year to date, according to government data released Tuesday.
The July on-time arrival rate of 69.8 percent was one of the worst monthly performances since the Transportation Department started keeping records in 1995, and it kept airlines on track for their worst-ever year for delays, cancellations and congestion.
More than 13,400 flights were canceled and 2,100 flights diverted in July.
In the first seven months of 2007, airlines operated 4.34 million flights and reported 1.08 million delays for an arrival rate of 72.2 percent. More than 106,000 flights were canceled, about 2.4 percent of the total.
Bad weather, limitations of the air traffic system, and airline problems like aircraft mechanical trouble, crew shortages, and scheduling changes account for most flight delays.
Summer is the peak travel season of the year, and the number of delays usually increases because of thunderstorms in the Midwest and East.