Here's a way to predict the weather for the upcoming year.
According to one of Clifton Johnson's 19th century informants, the weather on each of the twelve days of Christmas predicts what the weather will be for the coming twelve months. I'm assuming they mean only in terms of sunshine, precipitation and cloud cover. Otherwise, for this system to work January 1st would have to be hot and humid to accurately predict August weather. Even with global warming that's not going to happen (yet)!
Christmas in the past, according to Stephen Nissenbaum, used to be an amorphous season that sometimes lasted for months. I'm not sure where the concept of twelve days of Christmas first originated, but there are lots of significant twelves in the world: twelve months, twelve signs of the zodiac, twelve apostles, twelve tribes of Israel, twelve Olympian gods, twelve imams., etc. I recall learning that there was once a numerical system based on the number twelve, from which we get twelve inches in a foot, twelve items in a dozen, and twelve dozen in a gross. Wikipedia (of course) has an article about the number twelve.