Someone at work asked me what this phrase meant the other day. I just got around to looking it up. It refers to the weather condition when it is sunny but raining. I never knew there was a term for it. I always just thought of it as “Hawaii weather.” Apparently, the following phrases also mean the same thing:
“foxes are on a marriage parade”
“witches are doing their wash”
“a tailor is going to hell”
(source)
To these, I would add another:
“The Big Monkey in the Sky Is Peeing on Us, Violently”
Mine makes a hell of a lot more sense than that foxes’ marriage parade bullshit. Fucking illogical weather arcana!
UPDATE: Duh, I completely forgot the term “sunshowers.”
One thing that the Japanese use that confused me at first was “hana kin” or “flower Friday”. At first I thought it was just the Friday closest to pay day as that would be the day to go out and play pachinko or waste it on some other fun. Then I got to asking around and I was told, by a majority, that “hana kin” is EVERY Friday. Not quite the weirdness of your rain example, but still something that I hear a lot.