Lightning Safety: When Thunder Roars, Go Indoors


During the warm weather, thunder storms—and the lightning that comes with them—are common. In fact, according to Environment Canada, lightning flashes occur in Canada about 2.34 million times a year—including about once every three seconds during the summer.

So lightning poses a serious safety threat to workers, particularly those who work outside. For example, in New Brunswick, eight workers received electric shocks when the steel structure they were working on was hit by lightning.

Do you think you’re knowledgeable about lightning? Environment Canada looked at some of the most common beliefs about lightning to see separate fact from fiction.

#1: If it’s not raining, there’s no danger from lightning.

Fiction. Lightning often strikes outside of heavy rain and may occur more than 16 km away from a storm. If you can hear thunder, you’re at risk of being struck by lightning and should take shelter immediately—that is, when thunder roars, go indoors. Remain sheltered for at least 30 minutes after the last rumble of thunder.

#2: The rubber soles of shoes or rubber tires on a car will protect you from being struck by lightning.

Partly fact, mostly fiction. Rubber-soled shoes and rubber tires provide no protection from lightning. But the metal shell of a car provides a pathway for the lightning strike to flow around the vehicle provided the car has a hardtop metal roof (not a convertible). Although such vehicles don’t offer you absolute protection from lightning, you and others are much safer inside a car—with your hands in your lap—than outside.

#3: People struck by lightning carry an electrical charge and shouldn’t be touched.

Fiction. Lightning-strike victims don’t carry an electrical charge and so can—and should—be attended to immediately.

#4: “Heat-lightning” occurs after hot summer days and poses no threat.

Fiction. “Heat-lightning” is actually just lightning from a thunderstorm that’s too far away for thunder to be heard—but the storm may be moving in your direction. On some occasions, lightning from a line of thunderstorms may remain mostly in the air and not touch the ground, but this situation can change rapidly and you should seek shelter immediately when lightning is present.

If your workers are at risk of getting struck by lightning, the OHS Insider can help you protect them with:

In addition, the Canada Lightning Danger Map from Environment Canada shows the areas at greatest risk of being struck by lightning in the next 10 minutes. (Watch this video to learn how to use the map.)