A standard passenger vehicle is one of the safest places to be during a thunderstorm, offering a high degree of protection from a lightning strike. This safety is attributed to the vehicle’s construction, which manages the electrical current from a strike. When lightning hits a car, the metal shell shields the occupants, allowing the electrical charge to travel a path that bypasses the interior. This protection depends on the vehicle having a hard, metal shell and the occupants taking specific precautions.
The Science of Protection
The protection offered by a car comes from its metal body, which acts as a conductive enclosure. When lightning strikes the vehicle, the electrical current travels along the outer surface of the metal shell. This phenomenon directs the electrical discharge around the passenger compartment and safely to the ground.
The common belief that a car’s rubber tires provide insulation from the ground is inaccurate. Lightning carries millions of volts, and the few inches of rubber are not enough to stop the current from jumping to the ground. The tires are often damaged as the current passes through the steel belts to complete the circuit with the earth. The metal structure is the sole component responsible for diverting the electrical energy away from the people inside.
What to Avoid Inside the Car
To maintain the protective integrity of the vehicle, occupants must avoid contact with any conductive materials inside the cabin. This means keeping hands away from the steering wheel, door handles, and the gear shift. Any metal component connected to the car’s exterior body can become a path for the electrical current.
Occupants should also avoid using electronic devices plugged into the car’s power system, such as chargers or auxiliary devices. The electrical surge from a lightning strike can travel through the vehicle’s wiring and into these components. The safest action is to pull over to a safe location, turn off the engine, and wait out the storm with hands resting in one’s lap.
What Happens to the Car
While the occupants are protected, the vehicle itself will likely sustain significant damage if struck by lightning. The intense heat from the electrical discharge can cause pitting or burn marks on the exterior paint and body panels where the lightning makes contact. The antenna is a common strike point and may be partially melted or vaporized.
The high-voltage current often finds its way into the car’s electrical architecture, causing widespread failure. Sensitive electronic components, such as the engine control unit (ECU), GPS, and audio systems, can be instantly damaged and rendered inoperable. Furthermore, the current traveling through the vehicle can cause the rear window to shatter due to the presence of fine defrosting wires embedded in the glass. The tires are also frequently destroyed as the current passes through the internal steel belts on its way to the ground.
When a Car is Not Safe
The protective mechanism relies entirely on a complete, conductive metal shell, meaning not all vehicles offer the same level of safety. Soft-top convertibles, for example, do not provide the necessary metal enclosure to channel the current around the occupants. Similarly, vehicles constructed with non-conductive materials, such as fiberglass bodies, lack the essential metal structure for protection.
External hazards also compromise the safety of a parked vehicle during a thunderstorm. Parking under or near tall objects, such as large trees, creates a risk of falling debris. If lightning strikes a nearby tree, the tree can split or fall onto the car, causing severe physical damage. The safest course of action is to park in an open area, away from any structures or objects that could potentially fall.