[maximus_asinus]

I think you should do away with the clouds. I don't think it can be done without looking horrible. It is possible something similar could be used to represent fog though.

I'd probably stick to adjusting the level's hue and luminosity in indicate weather. For example on a scorching day there would be a slight yellow/orange hue to represent the intense heat. And when it transitions into rain, a blueish hue would be applied along with a gradual dimming (and flashes of lightning done with a yellow/white hue with increased opacity).

I do like the idea of a calendar. Will weather be determined by month / season?