Steve, we had damp in the hallway and behind the door in the second bedroom some time ago, but it was nothing to do with the rain - it was something to do with the A/C drainage (where the unit is in the second bathroom). There was some sort of leak in the pipes somewhere (sorry, not too technical!). Our keyholder, Mark, got Angel round and they fixed it all - needed replastering (I think) and repainting, which they did.
I just mention this, in case it's a similar situation. We're also ground floor. Fortunately, we haven't had any problems with all this heavy rain - save for the fact it's been freezing on these marble floors!!