showering during a thunderstorm

This might be a really stupid question, but as someone who's never lived in a place with such intense and longlasting thunderstorms before ...

I know the rule is not to shower during thunderstorms. The thing is, the forecast today is thunderstorms from 8 pm today - 5 am tomorrow. Does this really mean that people can't shower/use the sink/wash their hands for 9 hours?