Clout casting is here!
Never cast a clout till May be out. An old saying that means "Don't take off your winter clothing till..." well, that's where it all goes a bit odd. Most people think it means "ooo, it can get cold until the end of May". But actually, the very English Hawthorn is also known as the May Tree, and its blossom is called May. So it could mean, wait until May blossom is out: in London this year it's been around for a week or so already - as have some people, casting clouts.