Is there A way to prevent it? Because I want to make a scene in one of my movies with them outside when its raining, but I dont want them to get burned.

Have you tried putting a lightning rod on top of your roof?

y dnt u get high aspiration points then get a weather machine worked for me ..

Just check the weather report on either the TV or in the newspaper then if it says rain but no lightning you can film
or get high aspiration points and get the weather machine thing.
There is a cheat to get full aspiration points but it involves Boolprop.
obviously you type in boolprop testingcheatsenabled true .
Then you shift click on active sim->go to spawn-> Go to sim modder-> then go on the one to do with aspiration points and give yourself full points
I use boolprop and it's fine for me

What's a lightening rod and what does it do?

In real life, a lightning rod is a metal rod that sits on top of your roof. It is attached to a thin metal wire that gets buried underground. Basically it creates a short-circuit path for electricity to go through. So if lightning does hit your house, it will be diverted through the lightning rod to the ground and thus prevent it from hitting the electrical system in your house.

What about in the game? What does it do in the game?

It probably divert the lightning so it doesn't light your trees on fire, but I honestly haven't cared enough to noticed that.

I didn't even know there was one...lol.

Just save your game regularly, and if things do get burned, simply go back to your last saved game and replay the whole thing.