I've read that 80% of sunlight is passing through clouds. Now there a small clouds and big clouds so it should be some average. Is this true or is the amount of sunlight passing throug a cloud really much more depending on the size of clouds. Is it for instance on a totally cloudy day that only 30% is passing and on a nice summerday when a cloud comes by it is 90%. Probably it depend on how high in length the clouds are.
But perhaps even a more interesting question is, are all wavelengths passing though on the same level? So is uv-light passing even easy as infrared light? In my experience though when walking in the sun it feels that much more than 20% of those warm IR-rays are being blocked by clouds (even if they are very tiny). So is it possible that even 70% of the IR rays are blocked or perhaps relatively moren than visible light or UV-light?