Minecraft wiki entry for Sky_dimension, associated text: The Sky Dimension is an inversion of The Nether, where as the latter is basically a large cave with monsters and a massive open space within, the former are peaceful floating islands spawn surrounded by open space. The Nether may also be thought of as being a hell with The Sky Dimension being a heaven; although the hazards present in each dimension are similar, falling from the sky dimension is just as lethal as falling from a cliff into the lava ocean in the Nether.
The Sky Dimension, similar to the Nether, has weather disabled. This is likely explained by the fact that it is above the clouds.
Far Lands do generate in the Sky Dimension, but the way they generate looks completely different to the Overworld Far Lands.[8][9]