Yes, a hard-topped car is a safe place in a lightning storm. Keep windows up and avoid touching metal parts.
Why it’s safe
The metal body of the car conducts lightning around you to the ground (Faraday cage effect). Rubber tires are not what protects you.
Tips
- Keep windows closed.
- Don’t touch metal parts or the radio.
- Park away from trees.
- Wait 30 minutes after the last thunder.
Convertibles
Soft top convertibles are not safe.
Rule
“When thunder roars, go indoors.”
Physics
A car with a metal roof and body works as a Faraday cage in a lightning strike. Current travels around the outside of the metal shell and into the ground, leaving occupants largely unharmed. The rubber tires are not what protects you. The National Weather Service says a hard-topped vehicle is a safe place during thunderstorms.
- A lightning bolt can carry up to 300 million volts and 30,000 amps and heat air to about 50,000 F (27,700 C).
- Cars have been struck, with damage to electronics or tires, but occupants rarely injured.
- Convertibles, soft-top vehicles, motorcycles, bicycles and open-cab tractors do not provide protection.
Safety tips
Keep windows closed, avoid touching metal parts like door handles, radios and charging cables, and wait 30 minutes after the last thunder before leaving the car. Pull over away from trees and power lines, and turn on hazard lights. Do not shelter in small open structures such as picnic shelters. NOAA records show most lightning victims are outdoors.
Physics
A metal car acts as a Faraday cage, directing lightning current around the occupants to the ground. The CDC says a hard topped vehicle is a safe place in a storm, but convertibles, motorcycles and soft top vehicles are not. Rubber tires do not protect; the metal body does.
Safety tips
Keep windows closed, avoid touching metal parts like door handles and radio, and park away from trees. Wait 30 minutes after the last thunder.
Why vehicles protect
When lightning hits a vehicle, current flows around the metal body through the skin effect and discharges to the ground, a Faraday cage effect, as shown in high voltage tests at Pittsburgh in the 1990s. Occupants are safe as long as they avoid contact with metal. Windows are fine, but touching the door frame or gearshift is not recommended.
Storm driving rules
If lightning strikes close, pull over away from trees and power lines, turn on hazards and wait 30 minutes after the last thunder. Avoid flooded roads: 6 inches of water can stall a car and 12 inches can float it. Convertibles with fabric tops and motorcycles are not safe. About 10 percent of lightning victims die and survivors may have long term effects.
Based on data from the National Weather Service and the CDC
