The conditions for a dry lightning occur are the same as in any storm, the interaction between particles with different charges.

It is believed that cloud-to-ground lightning are vertical. But, according to research worldwide, these lightnings travel sometimes 10, 15, 20km horizontally and even some more. This results in a lightning strike without previous storm, with clear sky.

In January 2013, a security camera at the Rionegro airport in Colombia, registered a dry lightning hitting an airplane.

In another case, just a few days ago, this phenomenon affected more than 70 soldiers. This happened when, suddenly and without threat of rain, a lightning fell in the middle of the peloton.

For this reason, if in the distance you see a storm, experts recommend stopping any outdoor activity.