What is the most abnormal weather idiom?

A bolt from the blue _ Explanation of idioms

Pinyin: qí ng tiā n pā nī lī

Interpretation: Thunderbolt: thunder. It thundered on a sunny day. A metaphor for an unexpected and shocking event that suddenly happened.

Source: Song Luyou's poem "Four nights before the chicken crows": "Let Weng fall ill and suddenly get drunk. Just like a long time, the sky flies. "