“Lightning can strike from a clear blue sky”

It's a widely held belief that lightning only strikes directly beneath or very near a visible thunderstorm, often accompanied by rain and thunder. This understandable assumption stems from our most common experiences with electrical storms, where the crackling energy and bright flashes are clearly linked to the dark, imposing clouds overhead. If you can see blue sky, it seems logical that you are safe from a lightning strike.

However, the reality of lightning is far more complex and can be deceptively dangerous. So-called 'bolts from the blue' are a genuine meteorological phenomenon. These powerful lightning strikes originate from the top of a thunderstorm but then travel horizontally for significant distances, sometimes as far as 25 miles, before curving down to strike the ground. Because they detach from the main storm cloud and can occur so far away, they often appear to come from an entirely clear sky, catching people completely off guard.

The reason this misconception persists is due to the very nature of these strikes. Most people who observe a clear sky above them would naturally assume no immediate threat of lightning, especially if the parent thunderstorm is out of sight or too distant to be perceived as a danger. This lack of visible warning makes bolts from the blue particularly hazardous, as individuals may not take appropriate safety precautions, leading to a higher risk of injury or fatality. Understanding this phenomenon highlights the importance of seeking shelter (Review) even when a storm appears to be a long way off.