0 with clouds in the sky and therefore not bright and sunny -- 陰天的，多雲的；布滿陰雲的
a depressing, overcast winter morning 沉悶、陰暗的冬日早晨
The quality of light is indeed external and overcast, a quality maintained even without sufficient natural light.
If a building can be adequately lit on an overcast day, then the blue sky can provide twice as much light.
All indirect measurements were only taken during uniformly overcast sky conditions or after sunset (mostly after 1700 h).
The following night was overcast, pitch black and with no stars visible.
The natural light in the reading room is diffuse and directionless and, like the overcast sky, the light source is never seen directly.
On an overcast day, the light is very diffused and is about 5% of direct sunlight.
Trapping was carried out under similar general climatic conditions, avoiding rainy or heavily overcast days.
Readings were taken during overcast or cloudy conditions when diffuse light was predominant, as required by this method.
