also: つきがさ
noun
lunar halo; moon ring
A ring of light around the moon caused by ice crystals in the atmosphere. A somewhat poetic or scientific term; in everyday conversation, people often describe it as 月の周りの輪.
今夜は月暈が見える。
A lunar halo is visible tonight.
月暈は天気が崩れる前兆と言われる。
A lunar halo is said to be a sign of approaching bad weather.
Kana-mixed spelling for the reading つきがさ, avoiding the rare kanji 暈.
From 月 (moon) + 暈 (halo). The reading げつうん is the on'yomi, while つきがさ uses the kun'yomi for 月 and the kun'yomi for 暈.