Probably the most dangerous part of backpacking is driving between home and the trailhead. Driving home after the trip is probably worse because you are tired!

On the other hand, taking sensible precautions, such as staying off high exposed places during thunderstorms and taking sufficient insulation/rain gear to stay warm and dry in adverse weather conditions, is (or should be) only common sense. It's not something to spend a lot of time and energy worrying over, though!