I'm not planning to go any weather system yet. Right now I want uSky to be light weight and simple. Extra fancy addon feature I may implement it later that depends on how user like this asset. In the beginning, I didn't plan to add cloud in uSky. User can make their own solution, and many other cloud package assets are available too. The easiest way is that user can always place a simple hemisphere dome or couple planes on the sky for cloud texture map. In this case user need manually to apply the cloud color for different time of day . Some 3D cloud asset out there render very nice effects already, but it has to run on high-end platform. So right now I may just add also a simple solution that use static cloud texture for another layer in the skybox and change color automatically according to the light direction. I'm glad to hear any other suggestion or ideas as well.