More on rain from GKC:

There is a wild garment that still carries nobly the name of a wild Highland clan: a elan come from those hills where rain is not so much an incident as an atmosphere. Surely every man of imagination must feel a tempestuous flame of Celtic romance spring up within him whenever he puts on a mackintosh. I could never reconcile myself to carrying all umbrella; it is a pompous Eastern business, carried over the heads of despots in the dry, hot lands. Shut up, an umbrella is an unmanageable walking stick; open, it is an inadequate tent. For my part, I have no taste for pretending to be a walking pavilion; I think nothing of my hat, and precious little of my head. If I am to be protected against wet, it must be by some closer and more careless protection, something that I can forget altogether. It might be a Highland plaid. It might be that yet more Highland thing, a mackintosh.

And there is really something in the mackintosh of the military qualities of the Highlander. The proper cheap mackintosh has a blue and white sheen as of steel or iron; it gleams like armour. I like to think of it as the uniform of that ancient clan in some of its old and misty raids. I like to think of all the Macintoshes, in their mackintoshes, descending on some doomed Lowland village, their wet waterproofs flashing in the sun or moon. For indeed this is one of the real beauties of rainy weather, that while the amount of original and direct light is commonly lessened, the number of things that reflect light is unquestionably increased. There is less sunshine; but there are more shiny things; such beautifully shiny things as pools and puddles and mackintoshes. It is like moving in a world of mirrors.