To maximize your chances of an on-time departure, the "golden rule" in 2026 remains booking the earliest flight of the day, typically between 6:00 AM and 10:00 AM. Early morning flights are significantly less likely to be delayed because the aircraft has usually spent the night at the airport, meaning it isn't waiting for an inbound leg from another city. Furthermore, air traffic control congestion is lowest in the morning, and the "ripple effect" of cumulative delays across the network hasn't had time to build up. Additionally, in many regions, convective weather and afternoon thunderstorms—which often trigger ground stops—are less frequent in the morning hours. Statistically, on-time performance begins to drop after noon and reaches its lowest point in the late evening.