Endless rain

Or maybe it's just a PLAIN POLICE BOX

"Shhh, you'll upset the doctor who fandom!"

There haven't been real police boxes in Britain since the 1900s

More specifically they were used until the 1970s within London, until radios replaced them and became more efficient. There are still some left today, but they are non-functioning and left as sort of historical artefacts. There are still some functioning Police 'posts', which share a similar aesthetic design to the T.A.R.D.I.S. but instead of being boxes you step into, they are posts from which you can obtain a phone to call police or a first aid kit.