The sky in a dream commonly represents possibility and perspective -- how much room you feel you have to grow, or how far you're able to see beyond your immediate circumstances. A vast, open sky can reflect a sense of freedom, while a sky that feels low or closing in may point to constraints pressing on your sense of what's possible.
The Sun is in conflict with those who are ruled by Saturn, and Saturn is in conflict with those ruled by the Sun. - Picatrix (Andalusia, ~1000.AD)