Flights may be canceled due to wind, precipitation, fog or low visibility, lightning, low clouds, or storms. Outside temperature does not always affect flights. Pilots make the final determination as to whether a flight will occur or whether one in progress will be diverted to another airport.

Flights are rarely cancelled for lightning alone, but they are frequently delayed or rerouted to avoid the thunderstorms that produce it. Modern commercial aircraft are built to a "gold standard" of safety and are designed to act as a Faraday cage; when lightning strikes a plane—which happens about once per year for every commercial jet—the electrical current travels along the outer aluminum skin and exits through the tail or wingtips without harming the passengers or the electronic systems. However, the real danger is not the lightning itself, but the extreme turbulence, hail, and wind shear associated with the storm cells. Furthermore, ground operations at the airport must stop when lightning is detected within a certain radius (usually 5 miles) to protect the ground crew. This means that while your plane can safely fly through a storm, it cannot be fueled, loaded with bags, or marshaled to the gate until the lightning passes. So, while you won't see a cancellation solely "because of a bolt," the logistical "ripple effect" of a thunderstorm often leads to significant schedule disruptions.