Southwest Airlines in July had the best on-time performance among major U.S. carriers

at 83.1 percent, according to government statistics. It was followed by Frontier Airlines and Alaska Airlines. At 64.6 percent, JetBlue Airways ranked last among the 11 majors. Overall, the U.S. airline industry posted a July punctuality rate of 75.7 percent, better than both July 2007 (69.8 percent) and June 2008 (70.8 percent).