Oh I apologise, I thought you meant the water leaks out from under the car when ac on.
No your situation is not normal. Do you have a sunroof? If so I'd be checking the channels etc.
It could also be caused by failing door seals.
Or the water could be running front to back and in which case I'd be checking under the Skittles panel in the engine bay for any blocked drain holes.
Cheers
Steve