📖 Meaning
When a halo appears around the moon, wind is about to follow. The idiom is used metaphorically to mean that observing a small sign allows one to predict what is going to happen. It describes the ability to foresee future developments from early indications.
📜 Origin Story
The idiom originates from the essay 'On Distinguishing the Treacherous' (辨奸论) by Su Xun, a writer of the Northern Song Dynasty. In the essay, Su Xun wrote '月晕而风，础润而雨，人人知之' — meaning that when the moon has a halo wind will follow, and when the foundation stones become damp rain will follow, which everyone knows. He used these natural omens to argue that people should recognize the warning signs of treacherous officials before disaster strikes.
💡 Example Usage
老王常说月晕而风，所以一看到老板面色不善，就知道要出事了。
Old Wang always says a moon halo foretells the wind, so as soon as he sees the boss's grim expression, he knows trouble is brewing.
🏷️ Category
➕ Similar Idioms
➖ Opposite Idioms
🔤 Quick Facts
- Chinese: 月晕而风
- Pinyin: yuè yùn ér fēng
- Literal Translation: moon, halo, then, wind
- Category: Wisdom
- Characters: 4