Winter weather is one of the most reliable heralds of flight delays. And Avery, the first winter storm of 2018, was no exception. The storm contributed to 2,558 cancellations and 8,215 flight delays on its first day, with lingering effects on subsequent days. Weather is one cause of flight delays categorized by the U.S. Department of Transportation's Bureau of Transportation Statistics. It's part of a broader set of conditions known as the National Aviation System which also includes airport operations, heavy traffic volume, and air traffic control. Extreme weather is in its own category; it covers real and forecasted blizzards, tornadoes, and hurricanes. Delays also are caused by aircraft carriers and include problems with maintenance and crews, baggage loading, fueling, and aircraft cleaning. Security and safety issues that many people complain about—waiting in security lines for more than 29 minutes, broken equipment, and evacuation of aircraft—are others. Late-arriving aircraft scheduled for a trip later is the last type of delay the government tracks. Some flights have more problems than others, and Stacker analyzed data from the Bureau of Transportation Statistics to determine which flights out of your city’s airport have the worst records. We ranked airlines by overall on-time performance for all arriving flights in August 2018. We also included the total number of the airlines’ flights out of the airport and their overall on-time percentage. Flying out of Charlotte Douglas International Airport (CLT) sometime soon? Take a look at our list to see if it’s likely that your trip will go as scheduled or that you’ll spend more time in the terminal than you had planned before heading to your destination.