Cause of the encloudingEdit
If the Overcast can be attributed to Elder Sorcery, as above, this might explain why it still existed during the Interregnum. Alternatively, if it is in fact merely some sort of pollution from ordinary sorcery (as noted below), perhaps it was prevented from dispersing by the Gods so as to hide from the Jenoine that ordinary sorcery was no longer working.
It is thought to be an adverse effect of the use of sorcery, a form of magical pollution, which helps explain why the effect does not appear in the East, and the fact that the Enclouding is less prominent in certain areas of less habitation, especially near the sea. This theory is bolstered by information contained in the introduction (written by Brust) of the non-canon Dzurlord novel.
Dragaera may not have a moon. While the stars and starlight as a source of light in the night are frequently mentioned in the novels where the eastern sky is discussed (Jhegaala), the moon doesn't seem to come up as a topic as would be expected if the moon existed. The lack of a moon would imply weaker tides (although they would still exst due to the gravity of the furnace) and no eclipses.