Concept: Dungeon of Secret Years

Concept: Replace %chance activation traps with a rotation. 

Traps are divided into four groups, spread evenly across the dungeon. Only one group is active at a time. Once the PCs encounter an active object, the "season" advances and all current things turn off and the next group turns on.

Room 1: "Winter"
Room 2: "Summer"
Room 3: "Spring"
Room 4: "Fall"
Room 5: "Winter" 

It is currently "Spring" so PCs walk into Room 1 and it is safe and fine. PCs walk into room 2 and it is also safe. PCs enter room 3 and trigger the FALLING CEILING, making it "Summer" They retreat into room 2 where there's now MECHANICAL SNAKES! The snakes attack and then slither away, making it "Fall." They retreat again into Room 1, which is still safe. They eventually venture back to room 2, which is empty now. Room 3's ceiling refuses to fall, making it difficult to find the trigger. 

I like it as a mechanical effect. Is there an in-world explanation?