It’s never fun when lightning strikes your car. Paint peels. All your electronics could be fried. Your tires could blow. And just to add insult to injury, the thunder’s going be a crash like you’ve never heard before. But as long as you’re not in a convertible, you’ll probably be safe as long as you don’t touch anything metal that connects with the outside. So the main thing to do if lightning strikes your car is to keep away from the car’s walls and windows. If you’re not moving, it’s a good idea to let go of the steering wheel as well. That’s probably all you’ll have time to do anyway.
Why is it safe to be inside a car in a thunderstorm?
Back in the days of steel-frame cars, a car was just about the safest place to be if lightning hit. It’s got nothing to do with the rubber tires or insulation. It’s because the steel turns the car into a Faraday cage. All the electricity from the lightning bolt goes into that steel frame and down to the ground. None of it goes into the middle of the car, where the net charge is always zero. That’s sometimes called the skin effect.
Newer fiberglass cars aren’t as good at this, but they’re usually still good enough. There’s a lot of copper wiring and metal piping in these cars. A lightning strike’s much more likely to fry your electronics in a fiberglass car, but you should still be fairly safe.
Soft-topped cars, convertibles, golf carts, tractors, bulldozers, and anything else that’s like that aren’t enclosed as far as electric current is concerned. There’s no way to get a Faraday cage going here. You’re pretty much sitting in the open if lightning strikes one of these vehicles. Avoid them at all costs during thunderstorms!
Don’t touch it!
Even enclosed cars aren’t perfectly safe in thunderstorms, but a lot of that’s got to do with someone touching something that’s connected to the outside of the car. That’s because you can completely ruin the skin effect if you touch anything that’s metal and links to the outside of the car. Now you’re making a circuit that connects the outside of the Faraday cage to the inside, which wrecks it.
Obviously you should avoid door and window handles. Don’t touch or open your door until you’re absolutely certain the lightning’s gone off the skin and into the ground, which should take a second or so. Definitely don’t step down to the ground!
A lot of things you wouldn’t expect connect to the outside. Anything electronic, like your radio, CD player, or CB mike, connects to the copper wiring of the car. This isn’t the time to fiddle with the radio stations.
Steering wheels and gearshifts connect to the drive shaft, but you’ll need them while you’re still driving. However, you’ve probably got a couple of seconds here before lightning sparks to the drive shaft, if it gets there at all. Pull over as fast as safely possible, place it in park, and get your hands off the steering wheel. You’re driving more slowly anyway because of the rain, right?
Ideally you’ll also be able to turn on the emergency flashers and turn off the engine, but that takes more time. If you can move fast enough, do it. Otherwise, wait a couple of seconds and do it then. As long as you’re off the road safely, that’s normally good enough for the first few seconds. But you’ll still want to do anyway, just to check the fuel lines. You don’t want to find out the hard way that they’ve been weakened or melted by the lightning!
Roll up the windows before lightning strikes
If lightning strikes, a fully enclosed car’s safer than an open car. Glass isn’t great for getting the skin effect, but it’s a lot better than air. If the window’s up, you aren’t going to be leaning with your elbow on the window frame and ruining your nice safe Faraday cage. It’ll help keep the sparks out. It doesn’t hurt that you’re also not going to get wet.
If you’re caught in the middle of a really wild thunderstorm with lots of intense lightning, it’s best to pull off the road and wait it out anyway. You’re not going to be able properly to see through the buckets of rain anyway. Turn off the engine, put your flashers on if needed, take your hands off the steering wheel and put them in your lap, and relax. Nothing is that urgent. It’s better to arrive a little late than not to arrive at all.