noun
low-level clouds; low clouds
Meteorological term for clouds with bases generally below 2,000 meters, such as stratus and stratocumulus.
今日は下層雲が広がり、すっきりしない天気です。
Today, low-level clouds are spreading, making for gloomy weather.
Mid-level clouds, typically between 2,000 and 5,000 meters, such as altostratus.
Compound of 下層 (lower layer) + 雲 (cloud).