The red sky in this painting is ''real.'' It is a depiction of ''Krakatoa twilights'' which occurred in northern Europe through the winter of 1883-1884 as a result of the eruption of volcano Krakatoa in Indonesia .Most Europeans were overwhelmed (to say the least) when they were confronted by the awesome volcanic red skies
Although ''The Scream'' was not painted until ten yrs later, the red skies had made their impact on Munch's already-sensitized psyche