Exterior Mains Outlet Socket

Does anyone know just how waterproof the mains socket outlets are that are built into the side of the van, as they do not appear to be stamped with an ip rating (ip66 total water and dust proof, ip 56 heavey splash proof, ip55 light splash proof). The reason that concerns me is, on my previous van the socket was in the awning and so was dry. I would plug in a chest fridge (marvellous for endless supply of cold beer). On my new van the socket is going to be outside the awning and the fridge still inside. Anyone have any experience of these sockets being exposed to the elements?