I encountered 五月雨式に失礼いたします in a business email today. Microsoft's embedded translator in Outlook says:
Excuse me for the May rain ceremony.
So I took a closer look at the email and sure enough that's exactly what the original text says. But I knew there must be some deeper meaning given the context. Google translate has a less literal translation:
Please excuse the ominous atmosphere.
But that doesn't seem to match the writer's intent. Deepl came up with:
If you'll excuse me, sir, I have to take a rain shower.
Or British English:
I beg your pardon in the manner of the May rain.
MS CoPilot seems to be able explain it though:
The phrase "五月雨式に失礼いたします" (samidare-shiki ni shitsurei itashimasu) is a polite Japanese expression often used in business or formal communication. It translates to "I apologize for the repeated interruptions" or "I apologize for the frequent messages." The term "五月雨式" (samidare-shiki) literally means "in the style of early summer rain," which is a metaphor for something happening repeatedly or intermittently.
And Perplexity did a good job as well:
The phrase "五月雨式に失礼いたします" (samidare-shiki ni shitsurei itashimasu) is a polite Japanese expression used primarily in business communication. It can be translated as "I apologize for the repeated interruptions" or "Excuse me for the continuous disturbances."