The Ninjago Sky is above all of Ninjago. It was once going to be the location of another reborn realm, but this is no longer the case. It is also where a Temporal vortex appeared on various occasions when one was created by the Time Blades.
The temperature in the Ninjago Sky is around 59°F or 15°C. Up there, the air is thin and cold.
The images on Ninjago Sky need to be organized.