star on a rainy night; rare occurrence; rare sight
Literally a star visible on a rainy night, used figuratively for something very rare or a rare and precious sight. Often carries a poetic or literary tone.
See also: 雨夜
His talent is truly like a star on a rainy night—a rare and precious sight.
こんなに美しい夕焼けは雨夜の星だ。
Such a beautiful sunset is a rare sight, like a star on a rainy night.
The expression combines 雨夜 (rainy night) and 星 (star), evoking the image of a star that is rarely seen due to cloudy, rainy conditions. The exact origin is uncertain, but it is used as a poetic metaphor for rarity.