The autumn weather is moody, but why is the dark cloud so dark? Rain clouds are much thicker than those that are fluffy, unobtrusive, and shower-free. The larger the water droplets in the cloud, the better the ability to absorb sunlight. In the fluffy white cloud, tiny droplets scatter light, giving the cloud a white color.
Larger droplets in heavier clouds also scatter light, but they scatter too well, so that when the sun reaches the bottom of the cloud, the human eye looks like it is not much bright. Therefore, the bottom of a thick rain cloud usually looks dull and ominous….
This is why the fall is overcast.