also: かうん
noun
summer cloud; summer clouds
Refers to clouds seen in summer, often cumulus clouds associated with hot weather.
青空に夏雲がもくもくと浮かんでいる。
Summer clouds are billowing in the blue sky.
夏雲がわき上がるように空に広がった。
Summer clouds spread across the sky as if welling up.
On-reading, rarely used; mainly in literary or poetic contexts.
Specifically refers to towering cumulonimbus clouds, while 夏雲 is a broader term for any summer cloud.
Compound of 夏 (summer) and 雲 (cloud). The on-reading かうん is a Sino-Japanese reading of the same characters.